Commuters rioted last night in Buenos Aires, destroying the ticket offices of the city's largest train station and hurling rocks at police after their anger at rush hour delays boiled over.

Thousands of passengers were caught up in an exchange of tear gas, rubber bullets and rocks as the police moved in to control small groups of protesters who reacted to the cancellation of their evening services by smashing ticket stands and ramming their way into the station's police office.

A motorcycle was stolen from a station employee and set on fire on one of the platforms.

The four hours of fighting at Buenos Aires’ Constitución station, one of the busiest in Latin America, with 450,000 daily passengers, spilt into a nearby street as the demonstrators shattered windows, looted shops and ripped pay phones from walls.

Police said that 21 people, including nine officers, were injured, mostly by flying rocks, and 16 were arrested in the clashes, which came after months of mounting anger at delays, cancellations and chaos on the "Roca" train line that serves the mainly poor southern suburbs of the Argentinian capital.

Fernando Jantus, a spokesman for Metropolitano, the company that operates the line, said the protests followed the breakdown of two trains ten stops from Constitución, which paralysed the station at the beginning of the evening rush hour. “The problem happened at the worst moment,” he said

La Nación, a Buenos Aires newspaper, reported that the frustration grew as thousands of people filled the cavernous main hall of the station and learnt that trains to La Plata, Glew and Ezeiza would not be running at five o'clock yesterday afternoon. An hour and a half later, with no sign of services improving, a group of passengers rammed their way into station's police office and set fire to it.

The violence spread when Metropolitano announced that the fault could not be fixed on its electric line and that it would not be able to lay on diesel trains to take people home.

At that point, bins were set on fire and a group of protesters, among them recently sacked employees of the dairy conglomerate, Parmalat, destroyed the station's ticket offices. Metropolitano is owned by Sergio Taselli, a controversial local businessman who also runs Parmalat's Argentinian concession and the former employees are believed to have been already holding a protest when the station came to a halt.

Argentinian government officials blamed the intensity of the riots of groups of hooligans who came into the station intent on causing as much damage as possible, but anger has been mounting for months at the poor operation of the Roca line and Metropolitano's failure to inform passengers about changing routes and maintenance work.

Last September, commuters in Buenos Aires set three train carriages ablaze after services were cancelled and police made seven arrests. The city's suburban lines were privatised in the 1990s under then-President Carlos Menem but passengers for years have complained about the failure of new operators to provide a decent service.

Times Recommends

• Michael Jackson: Not the final chapter
• Indian Army spends10m rupees on golf buggies
• Sacha Baron Cohen forced to tone down Brüno