NATO and Afghan forces killed 94 Taliban fighters in airstrikes and ground attacks in southern Afghanistan, while a homicide bomber on Sunday killed a provincial governor in the east, amid deepening violence across the insurgency-wracked country.

The U.S. military, meanwhile, said that a homicide bombing cell was operating in Kabul, with the aim of targeting foreign troops. The warning came two days after a car bomber rammed into a U.S. army convoy near the U.S. Embassy, killing 16 people, the worst such attack in the capital.

"This cell is alive and working and remains very much a threat," Col. Tom Collins, the chief U.S. spokesman, told a news conference in the Kabul.

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Afghanistan is facing its worst upsurge in violence since the U.S.-led ouster of the Taliban regime nearly five years ago for hosting Usama bin Laden. While insurgents have stepped attacks across the country, the heaviest fighting has been focused on the south.

NATO said the 94 militants were killed in Kandahar province's Panjwayi and neighboring Zhari districts late Saturday and early Sunday, pushing the toll from a nine-day counterinsurgency operation there past 420. Five NATO soldiers and 14 British crew of a reconnaissance plane have also died.

NATO announced that two U.S.-led coalition soldiers, working with the Afghan army, had died in combat late Saturday — one in the NATO-led offensive in Panjwayi, the other in neighboring Zabul province. It did not give their nationalities, but most troops in the coalition are American.

Operation Medusa began Sept. 2 in Panjwayi, where hundreds of militants had mobilized just 15 miles west of the main southern city of Kandahar city — the former seat of the Taliban government. It's one of the most intense military confrontations since the U.S.-led campaign that toppled the Islamist regime.

NATO said in a statement that the latest insurgent casualties were inflicted in four separate engagements using artillery and air strikes.

There has been no independent confirmation of the casualty numbers given by NATO. Purported Taliban spokesmen have disputed them.

But the anti-insurgent blitz comes amid concerns that NATO lacks enough troops to succeed in its mission.

In Poland, Gen. Ray Henault, chief of NATO's military committee, said Saturday he would formally ask the alliance's 26 member states on Monday to provide up to 2,500 more troops to supplement the 8,000 mostly British, Canadian and Dutch forces it already has in the volatile region.

Meanwhile in eastern Afghanistan, a homicide bombing killed three people including the governor of Paktia province outside his office on Sunday, and wounded three, police said.

The attacker, with explosives attached to his body, ran into a car carrying Gov. Abdul Hakim Taniwal, his nephew and a bodyguard, killing all of them as they left the office in the Paktia capital of Gardez, U.S. and Afghan officials said. Taniwal died of his wounds in hospital.

Mohammed Hanif, who claims to speak for the Taliban, claimed responsibility in a satellite phone call to an Associated Press reporter in Pakistan. Hanif said the attacker was an Afghan from Paktia province and threatened more attacks.

"Our mujahedeen will conduct similar attacks. We have prepared a group of self-sacrificing attackers," he said.

Taniwal had been governor of Paktia for about one and half years. Before that he was federal minister of mines and industry in the Cabinet of President Hamid Karzai.

Taliban-led militants have increasingly adopted tactics reminiscent of insurgents in Iraq, including homicide attacks.

Collins said that the coalition had had intelligence that a bomber was in the city before Friday's devastating attack near the U.S. Embassy but lacked a description of the attacker or the vehicle he was using.

"The coalition had intelligence that a suicide bomber was lurking in Kabul. What we didn't have was a description of the attacker or license plate for his vehicle, but somehow I believe somewhere out there someone knew this guy and had information that could have saved a lot of lives that day had they reported it," he said.

Meanwhile, in western province of Farah, more than 100 Taliban fighters raided a government compound, killing two policemen and setting fire to several buildings, said provincial police chief Sayed Agha.

Taliban fighters riding in pickup trucks and firing rocket-propelled grenades and AK-47 assault rifles attacked the compound in the town Kalaigar at about 1 a.m. on Sunday. They also burned two rooms of the compound and a health clinic in the town before fleeing.

Agha said the Taliban raid was the first in Kalaigar. Resurgent Taliban fighters have been most active in southern provinces. But attacks have started occurring in the west amid intense NATO military operations targeting Taliban in the south.

Separately, Taliban militants killed three Afghan soldiers and wounded eight in an ambush in southern Zabul province's Shahjoy district Saturday, said Defense Ministry spokesman Gen. Zahir Azimi.

Afghan authorities also found the body of a district education chief Saturday who was kidnapped by suspected militants in central Ghazni province, said Abdul Ali Faquri, a spokesman for the provincial governor.

U.S. soldiers killed two suspected militants Sunday in a mortar barrage in the eastern Kunar province's village of Darbart after they had fired on an American-Afghan army patrol, said Command Sgt. Maj. Jimmy Carabello.

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