Angry mobs in Argentina have burned train cars in at least three stations after a derailment caused long delays in Monday's commute.
Police say the mobs also attacked ticket booths, train conductors and officers who tried to restore order.
Huge plumes of smoke went up from at least three trains along the Sarmiento line, which links the capital with western suburbs.
Dozens of people were involved and several were arrested.
Buenos Aires Trains spokesman Gustavo Gago says it's not easy to set a train on fire, but the mobs appeared to be well-organized, destroying security cameras and coming prepared to for the arson attacks.