Yemeni anti-government protesters hold up posters of Argentine Marxist revolutionary Che Guevara and senior Yemeni officials with an inscription in Arabic reading: 'Wanted' (left) as they march to demand the trial of Yemen's outgoing President Ali Abdullah Saleh in Sanaa, Yemen, Dec. 1. At least five people were killed in an attack by forces loyal to Yemen's outgoing President Ali Abdullah Saleh on the southern city of Taiz, the Yemeni news website Al-Masdar reported. Fifteen were injured, some seriously, when the pro-Saleh troops shelled the city, the report quoted a medical source as saying. Taiz has been a focal point of anti-Saleh protests that have gripped the impoverished Arabian peninsula country since February.

Yemeni protestors march during a demonstration demanding the prosecution of Yemen's President Ali Abdullah Saleh in Sanaa, Yemen, Thursday, Dec. 1.

Yemeni anti-government protesters shout slogans as they march to demand the trial of Yemen's outgoing President Ali Abdullah Saleh in Sanaa, Yemen, Dec. 1.

A Yemeni wounded protestor is carried from the site of clashes with security forces in Sanaa, Yemen, Tuesday, Oct. 25, 2011.

A 14-year-old wounded Yemeni pro-reform protester is treated at a makeshift hospital near Sanaa's landmark Change Saqure on October 25, 2011, after government troops opened fired on tens of thousands of protesters.

Military policemen carry the coffins of police officers killed during recent clashes with armed followers of the tribal leader Sadiq al-Ahmar during a funeral ceremony in Sanaa October 21, 2011.

Military police sit by the coffins of police officers killed during recent clashes with armed followers of the tribal leader Sadiq al-Ahmar during their funeral in Sanaa October 21, 2011.

Anti-government protesters rush a wounded fellow protester on a motorcycle after clashes with supporters of Yemen's President Ali Abdullah Saleh and police in Sanaa on October 18.

Protesters march during a demonstration demanding the resignation of Yemen's President Ali Abdullah Saleh in Sanaa, Yemen, on Oct. 18,. Fighting between troops loyal to Yemen's embattled leader and rival forces on Monday killed several people, including eight supporters of a powerful tribal chief who defected to the opposition in March.

Anti-government protesters carry a wounded fellow protester after clashes with supporters of Yemen's President Ali Abdullah Saleh and police in Sanaa October 18.

Supporters of Yemeni President Ali Abdullah Saleh gather in a main square in Sanaa on Sept. 23 to celebrate his return to Sanaa, even as his forces were battling dissident troops in the capital.

Yemeni security forces and supporters of President Ali Abdullah Saleh carry the coffins of comrades killed in recent battels with dissidents during a mass funeral in Sanaa on Sept. 23. The funeral coincided with a rally held in the capital to welcome the president's return home after more than three months of medical treatment in Saudi Arabia.

Men shout slogans celebrating the return of Yemeni President Ali Abdullah Saleh in Sanaa, Sept. 23. According to media reports, Yemeni President Ali Abdullah Saleh returned to the capital Sanaa after more than three months in Saudi Arabia, where he had undergone treatment for injuries sustained in a bomb attack on the presidential palace in early June.

A soldier stands guard as anti-government protesters gather during a rally before Friday prayers to demand the ouster of Yemen's President Ali Abdullah Saleh in Sanaa June 24.

A girl attends the weekly Friday prayers with her mother during a rally to demand the ouster of Yemen's President Ali Abdullah Saleh in the southern city of Taiz June 24.

Anti-government protesters sit atop a billboard during a rally before Friday prayers to demand the ouster of Yemen's President Ali Abdullah Saleh in Sanaa June 24.

A wounded anti-government protester receives treatment at a makeshift field hospital during clashes with Yemeni security forces in Sanaa late on April 27 in which at least 12 people were killed.