Five US soldiers were killed in a coordinated ambush in the northern Iraqi city of Mosul today, the US military said, making it one of the single deadliest attacks against American forces in months.
The patrol was hit by a roadside bomb and then came under small arms fire, the military said, the day after extra Iraqi troops arrived for a final push against al Qaeda in what has been described as their last major urban stronghold.
Iraqi defence ministry spokesman Major-General Mohammed al-Askari said Iraq was studying the prospect of temporarily shutting the border with Syria as part of the offensive intended to stop foreign fighters joining al Qaeda.
"It would be a very important step do prevent al Qaeda from reinforcing its ranks from outside," Askari said, adding aircraft would monitor the frontier. Most foreign fighters entering Iraq come across Iraq's porous border with Syria.
Violence has fallen sharply across Iraq, with attacks down 60 per cent since last June. But northern Iraq remains the biggest security worry after al Qaeda regrouped in Nineveh, of which Mosul is the capital, Salahuddin and Diyala provinces.
Few other details about the attack in Iraq's third-largest city were immediately available.
Iraqi army and police also reported that fighting had broken out in the Haysuma neighbourhood, a known al Qaeda stronghold in the east of the city, 390 km (240 miles) north of Baghdad.
Brigadier-General Khalid Abd al-Sattar, the operations spokesman for Iraqi security forces in Nineveh, said clashes erupted just after noon (0900 GMT) and that only US soldiers were involved in the operation. Fighting ended just before dusk.