The Sri Lankan country's human rights minister claimed Tuesday his country's army took over two months longer to defeat the Tamil Tiger rebels because it avoided using heavy weapons and aerial bombardments.

The army suffered heavy casualties in the final phase of Sri Lanka's civil war because it was constrained to use light weapons, Mahinda Samarasinghe told the U.N. Human Rights Council.

Rights groups and senior U.N. officials have said the Sri Lankan army shelled civilians, leading to thousands of deaths.

But Samarasinghe said "the reason that complete military dominance took a further 2 1/2 months was that our security forces were under strict instructions to avoid the loss of civilian life."

The government proclaimed victory last week in the 25-year insurgency by the rebels, who sought to create an independent Tamil nation for the ethnic minority in Sri Lanka's north and east.

According to U.N. estimates, some 7,000 civilians were killed in fighting since January.

The U.N.'s High Commissioner for Human Rights told an emergency meeting of the council last week that an international investigation team should be sent to Sri Lanka to examine the conduct of both the army and the rebels.

Navi Pillay said they should examine allegations that the Tigers prevented civilians from leaving the conflict zone, and that government forces used heavy artillery on the densely populated conflict zone and killed rebels trying to surrender.

But the 47-nation council, which is dominated by Asian, African and Muslim countries, rejected an investigation and instead praised the government for crushing the Tamil Tiger rebels.

U.N. spokeswoman Marie Heuze said Tuesday she was disappointed at the council's refusal to look into alleged abuses.

"It's a failure of the international community and of civil society," she told reporters. "It's a complete failure."

"The human rights council is the body to do exactly this," Heuze said.