Almotamar.net, Google - BAGHDAD, Jan 28 (Reuters) - Five U.S. soldiers were killed in a coordinated ambush in the northern Iraqi city of Mosul on Monday, the U.S. 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 percent 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 Monday's 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 U.S. soldiers were involved in the operation. Fighting ended just before dusk.

Soldiers on the ground were supported by helicopters, he said. A brief U.S. military report on the incident seen by Reuters said the area was later secured.

The U.S. military describes al Qaeda as the single biggest threat to security in Iraq.

Monday's attack against the U.S. patrol takes to 36 the number of soldiers killed in Iraq this month, up from 23 in December but similar to levels in October and November.

A total of 3,940 U.S. service personnel have been killed since the U.S.-led invasion to topple Saddam Hussein in 2003.



"DECISIVE" PUSH

Extra Iraqi troops, backed by tanks and helicopters, began moving into Mosul on Sunday after Prime Minister Nuri al-Maliki last week announced a "decisive" final push against al Qaeda in and around Mosul.

This came after a huge blast, blamed on al Qaeda by U.S. commanders, killed 40 people and wounded 220 in Mosul last Wednesday, according to security officials. The head of the Iraqi Red Crescent put the death toll at 50.

The blast was in an unoccupied building officials said was used by al Qaeda to store tonnes of weapons and explosives.

The U.S. military launched a series of offensives in the north and just south of Baghdad earlier this month.

Al Qaeda, blamed for most major bombings in Iraq, regrouped in Mosul after being squeezed out of western Anbar province and from around Baghdad during security crackdowns last year.

The overall improvement in security is credited in part to 30,000 extra U.S. troops, who became fully deployed last year, and the growing use of neighbourhood police patrols.

Another key factor has been a ceasefire by the feared Mehdi Army militia of Shi'ite cleric Moqtada al Sadr.

That truce expires at the end of February, and aides to Sadr have said it might not be renewed if attacks by security forces against the group do not stop.

Nassar al-Rubaie, the head of Sadr's political bloc in parliament, said no final decision had been made.