LONDON, March 28: US-led forces in Iraq can encircle the capital in days but lack the “overwhelming force” needed to wage warfare in the streets of Baghdad, a British defence source said on Friday.

He said the level of resistance witnessed by British forces in the south during the first week of war, especially around Iraq’s second city of Basra, showed the US-led campaign to seize control of Baghdad would be hard fought.

Pressure would instead continue from the skies — he called Thursday night’s US-led bombing the war’s heaviest — as part of a “hit hard and wait” campaign aimed at pressuring Iraqi President Saddam Hussein into defeat.

“The key thing is that US forces do not want to get involved in downtown fighting. It’s all about applying pressure with the result of the regime falling,” the source told Reuters on condition of anonymity.

“Basra is very interesting to watch as a precursor, an example of how Baghdad will be tough to crack,” he said.

British officials said on Friday that Iraqis had fired mortars and machine guns at about 1,000 civilians fleeing Basra as control of the city continued to evade ground forces.

Iraq said 116 people had been killed and 695 people wounded in Iraq’s second city since war began on March 20, with repeated reports of local uprising and fleeing Iraqis failing to translate into total control.

“It does represent the scale of resistance,” said the source, amid growing expectations war may prove longer and tougher than many pundits had first predicted.

President George W. Bush, after talks with top ally British Prime Minister Tony Blair on Thursday, made a clear attempt to extinguish expectations for swift victory, saying the war would be won — “no matter how long it takes”.

FIVE DAYS - OR QUICKER?: Military sources say predictions US-led troops could surround Baghdad in five to 10 days were “entirely plausible” and within the timetable.