BAGHDAD, June 13: US troops pressed at least three massive operations around Iraq on Friday, killing 27 assailants in the northeast, but their drive to take the battle to the enemy drew new tactics, with twin blasts hitting the main oil export pipeline to Turkey.

Officials also claimed that US troops had killed 70 guerillas in clashes on Thursday.

For the first time US commanders explicitly pointed to an involvement by the Al Qaeda network, saying 74 of its supporters had been detained in a raid near the northern oil capital of Kirkuk.

A US spokesman in Baghdad declined to give a casualty toll for a third major operation launched by US troops in northwestern Iraq before dawn on Thursday as it continued for a second straight day, but US commanders previously described it as “very lethal”.

The US-led forces launched new operations across north-central Iraq after taking a spate of casualties in recent weeks, but the renewed offensive failed to stem the widening attacks on troops from diverse resistance groups.

In the main northern city of Mosul, which a US commander, Lt Gen David McKiernan, hailed as a model of security just on Thursday, a US soldier was critically injured when patrols came under repeated handgrenade and sniper fire on the streets of the city centre.

Residents said those attacks were the work of former soldiers taking revenge following the US decision to dissolve all of Saddam Hussein’s armed forces with just a single, as yet unpaid, severance payment.

In the biggest operation, dubbed Peninsula Strike, launched on Sunday night by a brigade-size force between the towns of Balad and Baqubah, the 27 Iraqis were killed as they attempted a counterattack against US forces, the Central Command said.

“An organized group of attackers fired RPGs (rocket-propelled grenades) at a Fourth Infantry Division tank patrol in Balad on Friday,” a statement said.

“The tanks returned fire, killing four of the attackers, and forcing the remainder to flee.

“Tanks and Bradley Fighting Vehicles reinforced with AH-64 Apache helicopters pursued the enemy personnel killing 23 of the attackers,” it added.

‘CHEMICAL ALI’: In the town of Dhuluiya, just eight kilometres away, residents said another four Iraqis were killed on Thursday in a massive sweep for Ali Hassan al-Majid, a feared cousin of Saddam Hussein dubbed “Chemical Ali” for his role in the use of chemical weapons against Iraqi Kurds in the late 1980s.