Kabul, Afghanistan ? Coalition troops clashed with insurgents in two battles Saturday in fighting that left four U.S. and two Afghan soldiers dead and six other Americans wounded, officials said.

The fighting was reported to be some of the heaviest in recent months and came as war-battered Afghanistan celebrated its independence day.

During a clash against Taliban militants in eastern Kunar province, three U.S. soldiers were killed and three others wounded, said U.S. military spokesman Col. Tom Collins.

American troops in that area are hunting for Taliban fighters and extremists close to Osama bin Laden’s al-Qaida network in remote mountains hugging the Pakistani border.

In southern Uruzgan province, an American and two Afghan soldiers were killed and three other Americans wounded in a four-hour clash with more than 100 insurgents, according to a NATO statement.

The troops used artillery and air support to repel the insurgent attack, a NATO statement said.