OKA, QUEBEC, JULY 11 -- A provincial policeman was shot and killed near here today as about 200 entrenched Mohawk Indians and scores of flak-jacketed police officers fought a furious, day-long gun battle sparked by plans to expand a private golf course surrounded by tribal land.

The incident began about 5:30 this morning as police moved into the area near this Montreal suburb to tear down a barricade the Mohawks erected three months ago to block traffic to the disputed land, police officials said. They said shots were fired -- although it was not immediately clear by which side -- and the officers then lobbed tear-gas grenades into a Mohawk encampment near the barricade.

Police retreated, but returned about three hours later and staged a massive assault on the encampment with automatic weapons, stun grenades and more tear gas. About 200 Mohawks, their faces daubed with war paint and masked with bandannas, fought off repeated attacks over several hours, and were later joined by about 100 women and children from a nearby Mohawk reserve.

Police exchanged hundreds of rounds of rifle and pistol fire with the Indians but were forced to fall back as a stiff breeze blew tear gas across their lines, and the situation turned into a standoff. The Indians took advantage of the retreat to seize four police cars and two vans, then used a commandeered front-end loader to crush the vehicles into another barricade atop a hill on the main highway through the region. Their position overlooked a police roadblock at the bottom of the hill.

One police official said the assualt on the Indians was ordered "because the Mohawks were breaking the law" in setting up the road barricade. "They were blocking a public road, and this is a criminal act." The slain policeman was identified as Cpl. Marcel Lemay, 31, who died at a local hospital of a bullet wound to the face.

The dispute centers on land that has been owned by the town of Oka since 1947. The Indians have always maintained it is still theirs, and their Kahnesetake settlement surrounds it. Oka, 18 miles west of Montreal, leased the land to the operators of a private nine-hole golf course, who plan to cut down the pine forest that covers it and expand the course to 18 holes.

In a show of support for the Indians, armed Mohawks from the Kahnawake reserve south of Montreal set up car and truck roadblocks on two main highways leading to the Mercier Bridge, blocking thousands of residents on the south shore of the St. Lawrence River from getting to their jobs in Montreal.

Other Mohawk settlements on or near the U.S.-Canadian border have had similar confrontations with authorities in recent months.

"It always seems the Indian people, wherever they are, are forced into these positions," said Darryl Martin, a spokesman for the Mohawks in the Ganienkeh Mohawk encampment in northern New York. Ganienkeh was the scene of an 11-day armed standoff this spring after a National Guard helicopter was shot down over Indian land.

In May, police were called to the St. Regis Indian Reservation on the New York-Canadian border after an intra-tribal war over the presence of gambling casinos on the reservation resulted in two shooting deaths. Police peace-keeping units are still stationed on the reservation.