Taliban ambush Afghan police, 14 dead

KABUL (Reuters) - Eleven Taliban fighters and three policemen were killed when guerrillas attacked a convoy of provincial officials in southern Afghanistan, the government said on Tuesday.

In a separate incident, a roadside blast west of Kabul killed four Afghan aid workers, police said.

The attacks come after several days of some of the heaviest Taliban attacks since they were ousted in 2001 and just as NATO is bringing thousands of extra troops into the country.

More than 250 people have been killed since last Wednesday -- more than the number reported killed in Iraq during the same period -- according to figures from the U.S. military and Afghan authorities.

Most of the dead were militants but dozens of Afghan police, soldiers and civilians have also been killed, along with four foreign soldiers.

President Hamid Karzai ordered an investigation into the killing of 16 civilians in air strikes during an attack by U.S.-led forces on Taliban in the southern province of Kandahar on Monday.

The government convoy in Helmand, which included the provincial police chief, was traveling in the north of the province when it came under attack late on Monday.

"Three policemen were martyred and six were wounded," said Interior Ministry spokesman Yousuf Stanizai. Eleven Taliban were killed in subsequent fighting, his ministry said.

A Taliban spokesman, Qari Mohammad Yousuf, claimed responsibility for the attack and said there were no Taliban casualties.

The police chief in Maidan-Wardak province west of Kabul, Subhan Qul, said four Afghan aid workers, one of them a woman, were killed when a roadside bomb hit their vehicle on Monday.

An official at an agency overseeing security for aid workers said the four dead were a doctor, two nurses and a driver.

The Taliban, fighting to expel foreign forces and defeat the Western-backed government, have attacked and killed aid workers in the past, accusing them of supporting the government.

CIVILIANS KILLED

Authorities in Kandahar said the 16 civilians were killed in bombing by U.S.-led forces after Taliban took up positions in their homes. Some villagers said the toll was higher.

The U.S. military said it was investigating, adding that its forces had to be able to defend themselves against fire from known enemy positions.

Karzai condemned what he called the militants' use of civilians as human shields but also said he was concerned that U.S.-led forces had bombed civilian areas. He said he would summon the commander of U.S.-led forces for an explanation.

"On several occasions in the past, the president had called on coalition forces to be highly cautious to avoid civilian casualties," the president's office said in a statement.

Nearly five years after they were forced from power by U.S. and Afghan forces, the Taliban appear better organised and more aggressive than at any time since their ouster.

The militants have not managed to capture and hold territory but ever larger swathes of the countryside are off limits to government and aid workers at a time the government should be pushing its authority and development work into rural areas.

The violence is also disastrous for Afghan efforts to attract investment.

(Additional reporting by Mirwais Afghan in KANDAHAR and Yahya Nabawi in GHAZNI)