An Afghan fireman stands next to the debris of a car at the scene where a suicide car bomber attacked a NATO convoy in Kabul, Afghanistan, on May 16.

A U. S soldier secures the area where a suicide car bomber attacked a NATO convoy in Kabul on May 16.

A U.S. soldier arrives at the scene where a suicide car bomber attacked a NATO convoy in Kabul on May 16.

An Afghan man directs his children away from the scene of the attack.

The mother of 22-year-old Ayten Calim mourns during her funeral in the town of Reyhanli in Hatay province, Turkey, near the Turkish-Syrian border on May 14. Calim was one of around 50 people to have been killed by two bomb attacks in Reyhanli over the weekend.

Relatives cover the body of 22-year-old Ayten Calim with a Muslim prayer rug and her wedding dress as they lower her into a grave in the town of Reyhanli in Hatay province, Turkey, near the Turkish-Syrian border on May 14.

People stand in a damaged building on May 14, at Reyhanli in Hatay, Turkey, just a few miles from the main border crossing into Syria. The death toll in twin car bombings in a Turkish town near the Syrian border has increased to 50 after another body was recovered and a victim died in hospital, the health minister was quoted as saying on May 14. The attacks also provoked a backlash against the nearly 400,000 Syrian refugees in Turkey. Government officials have repeatedly warned against provocations and said Turkey will maintain its open-door policy for Syrians fleeing the regime's crackdown.

A man works in a damaged building on May 14 at Reyhanli in Hatay, Turkey, just a few miles from the main border crossing into Syria.

SWAT teams search for the remaining Boston Marathon bombing suspect in Watertown, Mass., on April 19.

A resident watches as police search an apartment complex in Watertown, Mass., on April 19.

A woman looks out a window at her home as police start to search an apartment building in Watertown on April 19.

Cousins Conor Gillis, 4, left, and Ben McCormick, 8, take part in a vigil on April 16, in Dorchester, Mass., for the victims of the Boston Marathon bombing.

People gather with candles during a vigil for eight-year-old Martin Richard, from Dorchester, who was killed by an explosion near the finish line of the Boston Marathon on April 16, at Garvey Park in Boston, Massachusetts.

People embrace during a vigil honoring the victims of the Boston Marathon bombings at the Boston Common in Boston, Mass., on April 16.

People gather for a vigil on Boston Common as an investigation continues into dual bombings at the finish line of the Boston Marathon in Boston, Mass., on April 16.

Emma MacDonald, 21, center, cries during a vigil for the victims of the Boston Marathon explosions at Boston Common, April 16.

People move items from a vigil after the barricade they were hanging on was taken down and a portion of Boylston Street reopened a day after two explosions near the finish line of the Boston Marathon in Boston, Mass., on April 16.

A woman places flowers at a barricade which has become a memorial site on Boylston St. at Berkeley St., a few blocks down from the two bomb sites in Boston, Mass., on April 16.

Aaron Jasper, left, and Jackie Pickering hold flowers outside the barricaded entrance at Boylston Street near the finish line of the Boston Marathon in Boston, Mass., on April 16.

Indian officials collect evidence at one of the two bomb blast sites in Hyderabad, India, early Feb. 22, after a pair of bombs exploded the previous evening.

Sujatha is overcome after seeing her husband Venkateshwarulu's body at a mortuary in Hyderabad, India, on Feb. 21. Her husband was killed in a pair of blasts in a crowded shopping area.

An injured man is carried to hospital from the site of a bomb blast in Hyderabad.

A member of the bomb squad with a sniffer dog arrives at the spot after a bomb blast in Hyderabad on Feb. 21.

Residents survey damaged houses following an overnight car bomb attack in Kirkuk, 180 miles north of Baghdad, Iraq, Dec. 17, 2012. On Sunday a series of blasts struck Shiite Muslim targets in the disputed northern city of Kirkuk, home to a mix of Arabs, Kurds and Turkomen, Each ethnic group has competing claims to the oil-rich area, the Kurds want to incorporate the area into their self-ruled region in Iraq's north, but Arabs and Turkomen are opposed, police said.

People inspect the scene of a car bomb attack in al-Mouafaqiyah, a village inhabited by families from the Shabak ethnic group, near the city of Mosul, 225 miles northwest of Baghdad, Iraq, Dec. 17.

A youth inspects destruction following two bomb blasts near a Shiite place of worship in the flashpoint town of Tuz Khurmatu in the Kirkuk province of Iraq, Dec. 17.

A Lebanese rescue man, carries an injured boy at the scene of an explosion in the mostly Christian neighborhood of Achrafiyeh, Beirut, Lebanon, on Oct. 19.

A man reacts near a burning car at the site of an explosion in Ashafriyeh, central Beirut, on Oct. 19. At least eight people were killed and 78 wounded by a bomb that exploded in central Beirut on Friday, the state news agency said.

Lebanese rescue workers and civilians carry an injured girl from the scene of an explosion in the mostly Christian neighborhood of Achrafiyeh, Beirut, Lebanon, on Oct. 19.

Firefighters extinguish fire at the scene of an explosion in Ashrafieh, central Beirut on Oct. 19.

Relatives comfort a wounded woman at the site of an explosion in Ashafriyeh, central Beirut, on Oct. 19.

Lebanese soldiers inspect damaged buildings at the scene of an explosion in the mostly Christian neighborhood of Achrafiyeh, Beirut, Lebanon, on Oct. 19.

Iraqi children play near bombed remains of vehicles in Khaldiya after a wave of coordinated attacks hit Iraq on June 13, 2012.

Iraqi men walk past the bombed remains of vehicles in Ramadi, after a wave of coordinated attacks.

People and security forces inspect the scene of a car bomb attack in the Karrada neighborhood of Baghdad, Iraq.

Residents gather at the site of a bomb attack in Kirkuk, Iraq.

A man wounded in a bomb attack is treated at a hospital in Kerbala, Iraq.

A wounded woman is helped at the scene following a bomb attack in Baghdad, June 4. A suicide bomber detonated explosives in a car outside Iraq's main religious affairs office for Shiite Muslims on Monday, tearing down part of the three-story building.

A wounded man is helped from the scene after a bomb attack in Baghdad, June 4.

Civil defense personnel work at the site of a collapsed building that was the target of a bomb attack in Baghdad June 4. A powerful car bomb exploded outside a Shiite Muslim administration office in central Baghdad on Monday, killing at least 26 people and wounding around 60 more, just days after six coordinated blasts rocked the Iraqi capital.

A man rides pauses to read signs outside a closed shop prior the funeral service of Melissa Bassi on May 21, in Mesagne, near Brindisi. Bassi, a fashion student, died on May 19 when a homemade bomb exploded at a vocational school just as she and fellow pupils were arriving for morning classes. Five other students were injured in the blast.

Flowers are displayed outside the Francesca Laura Morvillo Falcone school on May 21 in Brindisi, ahead of Melissa Bassi's funeral. Italian police have arrested two suspects over the bombing of a school that killed the 16-year-old girl and seriously injured five more teenagers.

A teddy bear and flowers are displayed in the classroom of Melissa Bassi at the Francesca Laura Morvillo Falcone school on May 21, in Brindisi, ahead of her funeral.

People gather at the scene of an explosion in Hodan district of Somalia's capital Mogadishu, on Feb. 17. A car bomb exploded next to a police department building in the Somali capital on Friday, wounding two police officers, the latest in a wave of attacks in Mogadishu.

A government policeman walks at the scene of an explosion in Hodan district of Somalia's capital Mogadishu, on Feb. 17.

A handout photo released by the official Syrian Arab News Agency shows Syrian security members gathering at one of bombing scenes that targeted security compounds in Aleppo, Syria, on Feb. 10. At least 25 people were killed and 175 injured in two explosions that targeted security compounds in Syria's second largest city, Aleppo, state television reported. The two blasts were the first to hit Aleppo, which has witnessed relative calm since the uprising against the Syrian president Bashar al-Assad started in mid-March.

Damaged cars are seen outside a military security building, one of two sites of bomb blasts in Syria's northern city of Aleppo Feb. 10, in this handout photograph released by Syria's national news agency SANA. Twenty-five people were killed and 175 people were wounded in two blasts targeting security bases in Aleppo on Friday, state television quoted the Health Ministry as saying.

A handout photo released by the official Syrian Arab News Agency shows Syrian rescue teams working at one of bombing scenes that targeted security compounds in Aleppo, Syria, Feb. 10. At least 25 people were killed and 175 injured in two explosions that targeted security compounds in Syria's second largest city, Aleppo, state television reported. The two blasts were the first to hit Aleppo, which has witnessed relative calm since the uprising against the Syrian president Bashar al-Assad started in mid-March.