University students began a 72-hour nationwide strike today in support of 43 trainee teachers who disappeared in the south-western state of Guerrero more than five weeks ago.

The trainee teachers from a college in Ayotzinapa have not been seen they clashed with police in the town of Iguala.

Iguala mayor Jose Luis Abarca and his wife Maria de los Angeles Pineda, who had fled the town in the aftermath of the incident, were arrested on Tuesday for allegedly giving the order to intercept the trainees.

A woman who had rented a house to the couple in Mexico City was also arrested on suspicion of aiding a fugitive.

The strike is the latest in a series of protests aimed at putting pressure on the authorities to intensify the search for the missing students.

Prosecutors have accused the mayor of telling the municipal police in Iguala to intercept the students to prevent them from interrupting a speech his wife was giving in the town that day.