Terre-Rouge, Haiti ? U.N. peacekeepers, criticized for inaction during their 10 months in Haiti, are taking on soldiers from the disbanded army in clashes that left two peacekeepers and two Haitian fighters dead — and the mission leader says more is to come.

The showdown signals a tougher stance against armed factions in Haiti ahead of fall elections and reflects a broader determination to crack down on militias that threaten civilians where U.N. troops are deployed.

The offensive in Haiti began Sunday when U.N. forces raided a police station occupied by armed former soldiers in Petit-Goave, 45 miles west of Port-au-Prince, setting of a gunbattle that killed two former soldiers and one Sri Lankan peacekeeper. The Sri Lankan was the first fatality suffered by the 7,400-member force since it arrived in June 2004.

Later Sunday, Nepalese soldiers driving to the central town of Hinche exchanged gunfire with a different group of former soldiers, and one Nepalese peacekeeper was killed, U.N. spokesman Damian Onses-Cardona said.

Brazilian peacekeepers, backed by armored cars and helicopters, then surrounded a stronghold of former soldiers in the town of Terre-Rouge in the Central Plateau region, where they were preparing Monday to retake control of another occupied police station.