Local and foreign militants fought a gun battle in north-western Pakistan, leaving at least 46 dead, the second such clash this month in a region where the government is urging tribesmen to move against al-Qa'ida-linked fighters.
At least two children were also killed and about 20 wounded when a stray mortar from the fighting in South Waziristan hit their school bus.
The clash between Uzbek militants and tribesmen broke out near the town of Wana on Monday and continued yesterday, a senior military official and a senior government official said.
They did not have further details on the allegiances and identities of the 46 dead.
"According to our information, at least 46 people died in the fighting between militants and tribesmen on Monday and Tuesday," the military official said.
No Pakistan army spokesman was available for comment.
But the two officials, speaking in Islamabad, said the clash was between pro-government tribesmen and foreign militants.
A senior diplomat in the Pakistani Embassy in Washington saidtribal leaders had given foreigners an ultimatum to get out of the region or surrender. When the Uzbeks failed to leave, fighting broke out. However, a local intelligence official said the fighting was part of a feud among militant groups.
A clash between tribesmen and central Asian militants in South Waziristan earlier this month killed 18 people.
Pakistan's government, an ally in the US-led war on terrorism, has long urged tribesmen to expel central Asia and Arab militants and faces fresh US concern that al-Qa'ida is regrouping in an area also viewed as a haven for Taliban fighters operating in Afghanistan.
However, the local intelligence official said the latest clash was not a simple conflict between pro- and anti-government forces in South Waziristan.
He said the fighting broke out over the killing of an unidentified Arab with suspected links to al-Qa'ida, who was an ally of local tribesmen led by a pro-Taliban leader, Maulvi Nazir. The Arab's body was found near a road bridge on the outskirts of Wana.
Local militants blamed the death on the Uzbeks, triggering a gun battle between the two groups in Kalosha, a village west of Wana, he said.
Some 13 Uzbeks and seven local tribesmen were killed in the fighting, and 35 others were wounded.
Among the wounded were five women injured when a rocket hit their home, he said.
He added that during the clash a stray mortar had hit a school bus, killing six children and wounding 20.
However, another security official said only two children were killed. It wasn't immediately possible to reconcile the different casualty tolls.
Pakistan's security forces have fought intense battles with foreign and local militants in recent years in the region as part of the government's efforts to crack down on al-Qa'ida and pro-Taliban forces.
But before this month, such clashes have rarely been reported.Reuse content