Updated

Chile police say they arrested 264 people and that 42 officers were wounded during a night of violence on the anniversary of Chile's 1973 coup.

Police say six officers were seriously injured when hooded vandals hurled acid at them.

President Sebastian Pinera visited the injured officers Thursday and asked the public to help identify the attackers.

Gen. Rodolfo Pacheco was taken by helicopter to a hospital after being struck in the head by an unlit gasoline bomb. Three public buses also were set on fire to make barricades in the streets of the Chilean capital.

The protests marked the 40th anniversary of the Sept. 11, 1973, coup that began Gen. Augusto Pinochet's brutal dictatorship. The government estimates 3,095 were killed during Pinochet's rule, including about 1,200 who were forcibly disappeared.