Some 1,000 locals set fire to a police station in an eastern Peruvian town yesterday and barricaded 25 police officers inside.

The attack was in protest against the police's use of tear gas, which affected children at an elementary school.

The incident occurred in Nueva Cajamarca district in San Martinprovince, some 1,000 km northeast of Lima, the capital city.

Mounting unrest in five Peruvian provinces has led to frequent clashes between police and demonstrators pressing various demands with local authorities or the central government.

Before the attack on the station, police had fired tear gas to clear the protesters near the school, causing several students to require medical attention and allegedly triggering the reaction of the local inhabitants.

Many students had to receive treatment after suffering from shock, gas inhalation and wounds sustained as they tried to flee the tear gas.

"We are in a critical situation. We are being attacked with fire guns, we need help please," one of the besieged policemen told a local radio station by phone.

The unidentified policeman also said that Cesar Gonzalez, the National Police colonel who commanded the operation, was attacked and detained by the mob when he tried to appease them.

According to a witness, the attack was followed by plunder, with further information about the besieged policemen yet to be known.