Mexico City, November 18 (NNN-RHC)-- The outrage spilling over into the streets in Mexico over the disappearance of 43 students near the town of Iguala in September appears to be leading to a showdown with the authorities, observers said. Violence has broken out in several parts of the city and there is no sign of the public anger dying down anytime soon.

Over a thousand students protested in Mexico City on Sunday, blocking a busy avenue with trash bins. The demonstration was called after two students were shot and injured by police at the Autonomous University of Mexico (UNAM) on Saturday.

After the peaceful demonstration ended, a group of around 20 masked students set oil containers on fire and threw rocks, smashing windows of a bank and a gas station in a business area located outside of the university.

Across Mexico, three caravans have started on their journey to various parts of the country to spread information on the case of the missing students and to gather local support. These caravans are due to meet up in Mexico city on Thursday for what observers consider it could be a showdown with the authorities.

A national strike is set to take place on Thursday, November 20th in protest of the presumed killing of 43 students from the Ayotzinapa teachers training college.

Last week, protesters attacked the regional headquarters of the ruling Institutional Revolutionary Party (PRI) building in Chilpancingo, the capital of Guerrero state. In another incident, protesters blocked Acapulco airport’s entrance for three hours. Three days before, demonstrators had attempted to storm the National Palace in Mexico City, setting the doors on fire after failing to get inside.

The public outrage was reignited by allegations from Attorney General Jesus Murillo Karam that three members of the Guerros Unidos gang had confessed to killing and burning the students' bodies later. It is alleged they were handed over to the gang by the police.