Protesters smashed up shops and clashed with riot police in Mexico City on the second anniversary of Enrique Pena Nieto's presidency, amid rising tensions over the abduction and apparent massacre of 43 trainee teachers.

Brandishing bats and fire bombs, masked protesters attacked banks and restaurants along the capital's Reforma Avenue where thousands had gathered to demand an end to impunity and justice for the missing students.

mexico missing students Ayotzinapa ya me canse
Demonstrators burn a picture of Mexico's President Enrique Pena NietoReuters
mexico missing students Ayotzinapa ya me canse
A smashed bank window is seen during a protest demanding justice in the case of the 43 missing studentsAFP
mexico missing students Ayotzinapa ya me canse
A bank branch burns after protesters hurled a Molotov cocktail into itAFP
mexico missing students Ayotzinapa ya me canse
Hooded demonstrators attempt to smash the windows of a bank in a shopping centre along Reforma Avenue in Mexico CityAFP
mexico missing students Ayotzinapa ya me canse
A student holds a national flag during a protest in Mexico CityAFP
mexico missing students Ayotzinapa ya me canse
Demonstrators participate in a protest in support of the 43 missing trainee teachers in Mexico CityReuters
mexico missing students Ayotzinapa ya me canse
A demonstrator holds up his hand with the number 43 written on it, in reference to the missing 43 trainee teachersReuters
mexico missing students Ayotzinapa ya me canse
Riot police clash with a group of demonstrators in Mexico CityAFP
mexico missing students Ayotzinapa ya me canse
Illustrations of the 43 missing trainee teachers are seen in Mexico CityAFP

Riot police were deployed to restore law and order, but authorities struggled to control the unruly crowd.

Similar protests were held in cities around Mexico, such as Acapulco and Chilpancingo.

mexico missing students Ayotzinapa ya me canse
People take part in a protest in Acapulco in Guerrero State – the same state where the students went missingAFP
mexico missing students Ayotzinapa ya me canse
A police vehicle burns after being set on fire by protesters outside the General Attorney's office in Chilpancingo, in the state of GuerreroReuters
mexico missing students Ayotzinapa ya me canse
Bishop Raul Vera releases a sky lantern in Saltillo after a mass in support of the 43 missing studentsReuters
mexico missing students Ayotzinapa ya me canse
A demonstrator pours fuel over a burning effigy of Mexico's President Enrique Pena Nieto during a protest in OaxacaReuters
mexico missing students Ayotzinapa ya me canse
Demonstrators in Monterrey hold a sign during a protest in support of the 43 missing trainee teachersReuters

The disappearance of the students has been the toughest challenge yet to face Pena Nieto. Earlier this month he vowed to introduce constitutional reforms to simplify Mexico's chaotic police structure and stop collusion between officials and drug gangs.

Pena Nieto took office two years ago vowing to restore order in Mexico, where about 100,000 people have died in violence linked to organised crime since 2007.

His two-year anniversary in office comes as his approval rating tumbles to just 39%, the lowest approval rating of a president recorded since 1996 when then President Ernesto Zedillo was struggling to contain a financial and economic crisis.

Feeding unpopularity is a scandal over a $3.75bn high-speed train contract. The government abruptly revoked the single-bid deal shortly before disclosures that the first lady was acquiring a luxury home owned by a company in the bidding consortium.