U.S.-led forces rained fire for two days on militants near Afghanistan's border with Pakistan, officials said Monday, killing about 55 insurgents and underscoring how fighting with Taliban insurgents is escalating.

The battle in eastern Paktika province was the second in the past week to reportedly inflict major casualties on militants, whom Afghan officials insist are swarming in from strongholds in Pakistan.

Pakistan's government on Monday reiterated an offer to fence the craggy, 1,500-mile frontier — a project begun but abandoned last year amid criticism that it would only enrage the tribes who straddle the frontier and among whom the Taliban find many recruits.

Charles Dunbar, professor of international relations at Boston University and former U.S. diplomat, said the unabated violence highlighted the need for regional and Western governments to seek political solutions to a conflict that shows no sign of easing.

As part of that, "Pakistan can perhaps do more than it is doing to control the free movement of the Taliban" as well as its current policy of seeking peace deals with militants on its side, he said.

Fencing the border is mainly a political figleaf for the hard-pressed Pakistani government, he suggested.

"This is an effort on their part to look busy," he said.

The battle in Paktika province began Friday morning, when militants armed with rockets and guns ambushed troops from the U.S.-led coalition patrolling a road in Ziruk district, the coalition said.

The troops returned fire and called in airstrikes.

"The fighting continued until Sunday morning. A majority of the casualties resulted from the close air support called to the scene," coalition spokesman Capt. Christian Patterson said.

Troops on the ground reported that about 55 militants died, 25 others were wounded and three were detained, Patterson said. He said no coalition troops died, but declined to say if any were wounded.

It was not possible to get independent confirmation of the death toll, but Nabi Mullakhail, the provincial police chief, said militants had suffered "huge" casualties in the remote, mountainous district. Afghan forces were not involved, he said.

The clash was the second in three days to inflict heavy casualties on insurgents, who have little answer to Western airpower.

The Afghan Defense Ministry said its soldiers counted the bodies of 94 militants after a joint operation with NATO forces Wednesday in Arghandab, a valley just outside the southern city of Kandahar.

The latest carnage means that June is already the bloodiest month this year.

According to an Associated Press tally based on statements from military and government officials, 465 people have died in insurgency-related violence so far this month, more than the 398 recorded in April.

For the year to date, the tally is nearing 2,000, most of them militants.

Mustafa Alani, director of security and terrorism studies at the Dubai-based Gulf Research Center, said violence was escalating also because of stepped-up military operations by the over 60,000 foreign troops in Afghanistan.

He said the Taliban were exploiting anger at reports of civilian casualties in military operations and successes such as a recent mass jailbreak in Kandahar to recruit new fighters.

The ethnic Pashtun tribes living on both sides of the border were also alienated by hollow promises of development aid. Meanwhile, the insurgents have become more adept at Iraq-style guerrilla tactics, including roadside bombs, he said.

"The number of casualties is not a measure of victory or defeat for them (the Taliban)," Alani said. "Those people are viewed as martyrs."

NATO said its forces prevented four militants from planting a bomb on a road in eastern Nangarhar province on Monday, but denied reports that two civilians also died, saying the fighting happened outside populated areas.

After a gunbattle, it said the troops called in air support, killing one of the militants. The others fled.

However, Zalmay Dadak, mayor of Khogyani district, said coalition fire during the overnight operation also hit a house in a village, killing a man and his son.

More than 100 villagers blocked the road in protest for several hours Monday.

Video footage of the scene obtained by Associated Press Television showed the corpses of a young man and a small boy lying on wooden beds under trees in the village on Monday.

Residents said a hole in the roof the family's house was caused by a shell. Several disemboweled cows and sheep lay nearby.

Civilians are regularly killed in clashes between militants and security forces, as well as bearing the brunt of insurgent suicide bombings.

On Monday, police said a car exploded in the western town of Shindand, killing four civilians and wounding another dozen in what appeared to be a botched suicide attack.

Local police chief Abdul Shuqur, citing witnesses, said that seconds before the blast the vehicle had approached a convoy of foreign troops. He said the troops opened fire when the driver ignored signals to stop.

NATO and coalition spokesmen said they had no information on the incident.

Coalition and NATO commanders blame militants for launching attacks from family homes and in towns. However, they also face criticism for using heavy firepower in residential areas.