(AP) - The U.N. peacekeeping force strongly warned the Khmer Rouge last week

after its guerrillas launched attacks in Preah Vihear and Kompong Thom provinces

that seriously breached the truce, a U.N. spokesman said.

The guerrillas have recently seized six villages near Phum Kulen town in Preah Vihear

province, said U.N. Spokesman Eric Falt. Government forces re-took the villages over

the weekend, he said.

In addition, they shelled the provincial capital of Kompong Thom, with shells landing

near the governor's house, the U.N. military observers' house, and the hospital,

said Falt.

But fighting flared again along Route 12, a strategic road in Kompong Thom that the

Khmer Rouge is trying to cut with heavy guns and landmines. Dozens of explosions

were heard over the weekend near the primitive road.

Falt said that while the truce violations were serious, they were limited to certain

areas and most of the country was reported calm.

He said the U.N. military command sent a "very strong" letter to Khmer

Rouge chiefs at their headquarters at Pailin. The letter said the attacks endangered

U.N. troops and would have serious consequences for the Khmer Rouge, Falt added.

The Khmer Rouge, violating a peace accord it signed last October, has been skirmishing

with Phnom Penh government forces and has refused to join the other Cambodian factions

in sending all troops to U.N.-supervised barracks.

Last week, U.N. Secretary General Boutros Boutros-Ghali said the Khmer Rouge defiance

"could ultimately jeopardize the whole peace process." But in a report

to the Security Council, he said he would nonetheless press ahead with the peace

process.

The Security Council is expected to issue a resolution soon on the Khmer Rouge problem.

Senior officials of France, one the the council's five permanent members, have urged

economic sanctions to force the guerrillas to comply with the peace accord.

In a statement distributed last week, the Khmer Rouge said it will send all its guerrillas

to U.N.-supervised barracks within a month if the Vietnamese-installed government

in Phnom Penh is dissolved during that period.

But the Phnom Penh government has rejected demands that it be dissolved. The peace

accord that the Khmer Rouge signed last October says the government is to remain

in place before elections next year.

The Khmer Rouge statement said that during the first week, the Khmer Rouge would

send 10 percent of its forces to barracks if the government agreed to "depo-liticize"

the ministries of National Defense and Public Security and abolish the ministers'

and vice ministers' jobs.

Another 50 percent would be sent to barracks in the following two weeks if more ministries

were dissolved, the statement said. It said the remaining 40 percent would go in

the fourth week, once all ministers and other high-ranking government officials were

gone.

The statement repeated demands for U.N. peacekeepers to verify that all Vietnamese

troops have left Cambodia, and for more power for the Supreme National Council, which

groups the country's four factions, including the Khmer Rouge.

U.N. officers say they have no evidence of significant Vietnamese forces remaining

in the country.