U.S.-led coalition forces and Afghan police killed or wounded 38 Taliban militants in Afghanistan as four suspected Al Qaeda operatives were arrested by coalition forces in the country's east on Saturday, officials said.

The latest violence came as a senior NATO official said a major operation to crush Taliban fighters in the south was moving to a close.

U.S.-led coalition and Afghan forces attacked a compound in southern Afghanistan on Saturday, killing 20 suspected Taliban militants, a coalition statement said.

The joint force used "superior fire and maneuver techniques and lethal close air support to kill" the suspected militants after they had attempted an ambush in Shahidi Hassas district of southern Uruzgan province, the statement said.

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There were no casualities among coalition or Afghan forces, it said.

Meanwhile, the Al Qaeda suspects, accused of planning attacks on coalition and Afghan forces, were nabbed near Sal Kalay, a village in Khost province, along with assault rifles and a briefcase containing "extremist-related documents," a coalition statement said.

It did not give the suspects' names, nationalities or indicate their possible seniority within the terror group.

Fourteen militants, meanwhile, were killed or injured by airstrikes and artillery in Garmser district of the southern Helmand province on Thursday, said provincial police chief Ghulam Nabi Malakhel.

District chief Ghulam Rasool said there was more fighting between militants and police on Saturday but he had no information on any casualties.

Four other suspected Taliban were killed in the Tagab district of the northeastern Kapisa province Thursday, after militants fatally shot a policeman and wounded three, said Yousef Stanezai, spokesman for the Ministry of the Interior.

A militant ambush in the same district later killed another policeman, and police arrested two suspected Taliban for the shooting.

Meanwhile, the commander of the NATO-led security force in Afghanistan said a massive U.S.-led offensive that has killed more than 600 suspected Taliban in the south will end when NATO takes over command from the coalition in the volatile region on Monday.

British Lt. Gen. David Richards, commander of NATO-led International Security Assistance Force, said the anti-terror coalition's Operation Mountain Thrust would wind down, but his 8,000-strong force of mostly British, Canadian and Dutch troops would "keep up the tempo" of operations against insurgents.

Since June 10, more than 10,000 Afghan and U.S.-led coalition forces have fanned out across the south, in response to an upsurge in Taliban attacks, sparking the bloodiest violence since the hardline regime's ouster in late 2001.

At least 19 coalition troops have died during the same period, according to an Associated Press count of coalition figures.

Richards said he did not expect the coalition — whose primary aim is to tackle militant groups such as Al Qaeda that are active in eastern Afghanistan — to now operate much in the south where the resistance is led by Taliban militants bent on toppling the government of President Hamid Karzai.

NATO brings a new strategy to dealing with the Taliban rebellion: establishing bases rather than chasing militants, and is hoping to win the support of local people by creating secure zones where development can take place.

"I hope people who now are often being intimidated into supporting the Taliban" will have the resolve to reject them, Richards said.

NATO forces will also have to grapple with drug militias involved in the insurgency, although they have no counternarcotics mandate and are only meant to support Afghan security forces who will take the lead in anti-drug operations.

Afghanistan produces nearly 90 percent of the world supply of opium, the raw material of heroin, much of it smuggled to the West. Afghan government officials and police are among those believed to profit.

Meanwhile, gunmen killed four police deployed to prevent trafficking of antiquities from a historical site at Dawlat Abad in northern Balkh province, near the border with Uzbekistan.

Naserullah Stanekzai, deputy minister of information and culture, said the assailants were suspected to be smugglers.

On Saturday, police also arrested four militants in the eastern Paktia province, Stanezai said.