According to officials, the demonstrations resulted in 221 arrests. Four civilians and nine policemen were injured in Santiago and other parts of the country.

It was the first time since the return of democracy in Chile that the anniversary was commemorated under an elected Conservative government.

In weeks leading up to the coup’s anniversary, Piñera announced that police forces would be increased dramatically on September 11 in anticipation of violence, as had occurred in years past.

Despite the arrests and protests, Interior Undersecretary Rodrigo Ubilla said the coup anniversary was calmer than in previous years.

“So far, compared to what happened in recent years, the results are quite positive,” Ubilla said. “If one looks at the number of people injured, so far the situation was considerably calmer.”

In the Santiago Metropolitan Region, 85 people were arrested, with many of the arrests occurring late at night. Three police were injured after being shot with pellet guns – two were shot in the eye and one was shot in the face.

In lower income areas of Santiago such as the Peñalolen borough, stones were thrown at passing cars. Special police forces had to intervene in the Villa Francia neighbourhood to stop a gas station from being looted. Power outages affected 104,000 households – more than as many as last year – after lines were cut during demonstrations.

A march from Plaza de Los Heroes to the General Cemetery in the Recoleta Borough started off peacefully, but ended in riot-like conditions near the cemetery.

The march began at 10 a.m. and was led by the Relatives of the Disappeared Detainees Association – a group representing the more than 1,300 people who were disappeared (and killed) during the 17-year Pinochet regime.

More than 8,000 people participated in the march, which culminated with the hanging of a wreath inside the cemetery.

However, just as the wreath was being hung, a mob appeared in the streets near the cemetery. Authorities did not intervene right away, and the protestors managed to destroy trash cans, tear down traffic lights, throw stones at police officers and assault two TV news cameramen. The police then stepped in with water cannons and tear gas.

Later that day police were criticized for not intervening earlier, and the government announced it would review their reaction times and procedures during the riot.

During his speech Saturday in northern Chile, Piñera discussed the significance of the coup for Chileans. Gen. Augusto Pinochet led the coup to remove Salvador Allende, a member of the Socialist Party who was elected president in 1970.

Piñera recalled that when the 1973 coup “our democratic system cracked, but it was not a sudden or unseasonable death. It was rather an anticipated outcome although definitively avoidable for a democracy which was sick”.

At the time society was sick of “hatred, extreme polarization, lack of dialogue. The impression then was that government and opposition had proposed to destroy each other, and they achieved it”, said Piñera who nevertheless praised the transition period which begun in 1988 “we did it rightly and many describe it as an example”.

Piñera said the upcoming 2010 bicentennial celebrations were an opportunity to unify the country and “become the Chile we all dream about”.

He also addressed the government's concern over a hunger strike by Mapuche prisoners that has been going on for more than two months.