She said security forces were ''in the midst of an operation" to recapture the police post in an offensive that began at approximately 10 p.m.
An AP reporter who had seen Humala enter the municipal building about four hours earlier was ordered by police to go into a nearby hotel with other journalists minutes before the operation began. The crackle of automatic gun fire could be heard outside.
The three-day standoff began Saturday when Humala and a group of about 100 loyal gunmen seized the police station in the remote Andean town, about 275 miles southeast of the capital, Lima. Five police officers were wounded and 10 taken hostage.
A day later, authorities said, the group ambushed a police vehicle, killing four officers and wounding several others. A gunman who was gravely wounded in the incident later died, local media reported.
The group, which wants to establish a nationalist indigenous movement modeled on the ancient Incan Empire, had demanded the resignation of President Alejandro Toledo, accusing him of selling out Peru to business interests in Chile, a historic rival. Toledo refused to step down.
Humala's offer to surrender came as a 6 p.m. curfew imposed on the town went into effect -- part of a government-declared, 30-day state of emergency in the region that resulted in the deployment of 1,000 troops.
Earlier, Humala rescinded an earlier offer to lay down his arms, claiming the government had violated the terms of the deal.
