Updated

The new Afghan government is working to determine whether seven top Taliban leaders who surrendered and were then set free are ``war criminals'' and whether the decision to let them go was appropriate, the foreign ministry spokesman said.

Foreign Ministry spokesman Omar Samad told reporters that there had been no U.S. request to hand over the former justice minister and six other high-ranking Taliban officials. But Pentagon officials have said the new Afghan leaders are fully aware of the U.S. desire to have custody of certain Taliban and Al Qaeda leaders.

``We would expect that to be the case with these individuals,'' U.S. State Department spokesman Richard Boucher said in Washington.

A U.S. military team, meanwhile, set off for neighboring Pakistan Thursday to bolster recovery efforts at the site of an airplane crash that killed seven U.S. Marines — the worst American casualty toll of the Afghan campaign

A Marines spokesman at the base at Kandahar airport said the military tanker, used for in-flight refueling, apparently crashed into a mountain with its tanks full, in line with witnesses' accounts of a fiery explosion when it hit.

The team from Kandahar was to join U.S. and Pakistani recovery teams already at the site, three miles from the Pakistan military's Shamsi air base, a forward operations point used by the U.S. military in the war in neighboring Afghanistan. The area — in the southwestern province of Baluchistan, a remote region of rugged mountains and vast deserts — was sealed off by the Pakistani military.

The seven deaths were the worst U.S. casualty toll from the war in Afghanistan. At the Kandahar base, marines observed a moment of silence, as a chaplain commemorated the dead.

In other military activity, the Pakistan-based Afghan Islamic Press agency cited unidentified sources as saying that several American helicopters carrying about 50 troops arrived overnight at Khost, bringing the total to about 100 to 150.

U.S. ground forces and warplanes have gone into operation against a complex of caves, tunnels and buildings used as an Al Qaeda training camp at Zawar Kili, near Khost, in the mountains of eastern Afghanistan.

Samad told reporters Wednesday that the government was determining whether the Taliban officials were ``war criminals.'' They included Nooruddin Turabi, the one-eyed, one-legged justice minister, who drew up the militia's repressive version of Islamic law — including restrictions on women — and created the religious police to enforce it.

Negotiations on the surrender of ex-Taliban figures have recently frustrated the U.S.-led coalition as it pursues the remnants of the Taliban and Usama bin Laden's Al Qaeda terror network. Taliban supreme leader Mullah Mohammad Omar reportedly escaped during surrender negotiations after being surrounded in the mountainous north of Kandahar.

The seven Taliban leader were let go after they recognized the government of Prime Minister Hamid Karzai and promised to stay out of politics, said Jalal Khan, a close associate of Kandahar's governor Gul Agha.

``Those men who have surrendered are our brothers, and we have allowed them to live in a peaceful manner. They will not be handed over to America,'' Khan said.

The government was trying to determine who the seven men freed in Kandahar were and whether the decision to let them go was ``appropriate,'' Samad said that so far there had been no U.S. request for their handover.

Kandahar was the birthplace of the Taliban movement in the early 1990s, and Omar remained based there even after the militia took power in most of the country in 1996. It was the last major Taliban-held city to fall, with the militia's leadership agreeing to abandon the city in early December.

Meanwhile, in an attempt to bolster the new government's authority in the capital, Karzai ordered armed men to leave Kabul's streets and return to their barracks within three days or be put in jail, Interior Minister Younus Qanooni said.

The order allows only uniformed police on Kabul's streets, where fighters from various Afghan factions bristling with rocket launchers and automatic weapons have moved freely since the Nov. 13 departure of the Taliban. International peacekeepers in the city are also armed.