QARAQOSH (Iraq) • Iraqi forces advancing on Mosul faced stiff resistance from the Islamic State in Iraq and Syria (ISIS) group yesterday, despite the US-led coalition unleashing an unprecedented wave of air strikes to support the week-old offensive.

Federal forces and Kurdish peshmerga fighters were moving forward in several areas, but the militants were hitting back with shelling, sniper fire, suicide car bombs and booby traps.

ISIS has also attempted to draw attention away from losses around Mosul with attacks on Iraqi forces elsewhere in the country, the latest coming on Sunday near the Jordanian border.

Following a weekend visit to Iraq by US Secretary of Defence Ashton Carter, American officials said the coalition was providing the most air support yet to the operation.

"One week into Mosul operation, all objectives met thus far, and more coalition air strikes than any other seven-day period of war against ISIL (ISIS)," Mr Brett McGurk, the top US envoy to the 60-nation coalition, wrote on social media. The coalition spokesman, Colonel John Dorrian, said: "There were 32 strikes with 1,776 munitions delivered against Daesh (ISIS) targets for the week of Oct 17-Oct 23." He said those strikes had destroyed 136 ISIS fighting positions, 18 tunnels and 26 car bombs.

The offensive, launched on Oct 17, aims to retake towns and villages surrounding Mosul before elite troops breach the city and engage die-hard militants in street-to-street fighting.

On the eastern side of Mosul, federal troops were battling ISIS yesterday in Qaraqosh, which used to be the largest Christian town in the country. Army forces entered the town for the third day running but armoured convoys deployed around it were shelled from inside.

Federal forces also scored gains on the southern front, where they have been making quick progress, taking one village after another as they work their way up the Tigris Valley.

On the northern front, Kurdish peshmerga forces were closing in on the ISIS-held town of Bashiqa. Turkey, which has a base in the area, said on Sunday it had provided artillery support following a request from the peshmerga.

While an increasingly pragmatic ISIS has tended in recent months to relinquish some of its positions to avoid taking too many casualties, US officials said the group was mounting a spirited defence of Mosul.

If ISIS loses Mosul in Iraq, only Raqqa in Syria will remain as the last major city under the militants' control in either country.

AGENCE FRANCE-PRESSE