A marine spokesman denied the US forces were shutting off the city, 50 kilometres (30 miles) west of Baghdad. "We are not conducting any offensive operations in Fallujah," insisted Major TV Johnson.

Inside the city, armed men gathered in the street, toting assault rifles and rocket-propelled grenades bracing for an attack, the correspondent said. Earlier, marines gathered outside Fallujah.

Some 15 tanks were deployed on a road about one kilometre (less than a mile) east of a US checkpoint on the border of the city. They later withdrew from the area.

It was not immediately possible to check whether the barricades on the east and southern entrances to the city were still in place Wednesday evening.

Iraqis living in Fallujah said American troops had asked the local authorities to provide them with safe passage through the city, the correspondent said.

Elsewhere, the number of wounded from a mortar attack on an Iraqi Civil Defense Corps (ICDC) and army base by Saqlawi, north of Fallujah, rose to nine, a doctor said.

"We were nearby when the mortar hit an army and ICDC base. We rushed to the scene and helped evacuate seven wounded," said witness Ali Abdullah, 27.

Earlier in the village of Nuaimiya, some two kilometres (one mile) south of Fallujah, four people were wounded in a clash between gunmen and the US army, the doctor said.

Fallujah was rocked in April by some of the heaviest fighting in Iraq since the US-led invasion last year after rebels brutally murdered four US security contractors.

It has been relatively calm since the end of April when US troops handed over patrols to Iraqi police and a newly-formed Fallujah Brigade, an ad-hoc force of veterans of the disbanded Iraqi army.

The last known US marine patrol through the city was on May 10.

Hardline Sunni clerics and gunmen have overwhelmed the Iraqi security forces inside the city and instituted their own harsh brand of Islamic law that includes public floggings for alcohol merchants.

WAR.WIRE