The Pentagon is reporting several hundred Iraqis forces have been killed after U.S. troops came under fierce attack south of Baghdad Tuesday. As the war to topple Saddam Hussein enters its seventh day, reports are also coming in of an uprising against Iraqi rule in the country's second largest city of Basra in the south.

British military spokesman Lieutenant Peter Darling tells VOA he has no information about the scale or scope of this apparent uprising, but says British forces are firing on "targets of opportunity" from the outskirts of the city in what he calls an attempt to fully exploit the situation. "We haven't got any details yet about how widespread it is in Basra. What we can say is that it was started by an attack on the Baath party headquarters," he says. "We've also been trying to encourage them to turn against, or rise up against their tormentors really, I would say for want of a better word, this repressive regime, and it looks as if that may well have happened. There have been some firing of enemy mortars which have then been radared and targeted in by our artillery and neutralized."

A British journalist embedded with the military in the Basra region reported Tuesday that Iraqi troops have been firing on protesters, with British forces firing back at Iraqi troops from the outskirts of the city.

Earlier in the day, U.S. Defense Secretary Donald Rumsfeld could not confirm that an uprising in Basra had started but he did have a message of caution for Iraqi civilians trying to rise up against Saddam Hussein, at least while Iraqi forces are able to fight back. hope and pray they will do it at a time when there are sufficient forces nearby to be helpful to them rather than at a time when it simply costs them their life and it's a wasted life," says Mr. Rumsfeld.

Iraq's information minister strongly denies reports of an uprising in Basra.

With an advance group of U.S. army troops now about 80 kilometers outside of Baghdad, military commanders continue to say they the war is going as planned. But American forces are increasingly getting caught up in behind-the-lines battles with Iraqi troops and militias and Defense Secretary Rumsfeld is warning Americans not to expect any quick victory. "We're still, needless to say, closer to the beginning than the end," he says.

In Nassirya Tuesday, American Marines secured a hospital where they had come under fire from Iraqi paramilitary forces disguised as civilians. And, in what is being described as a major ground battle, the Pentagon says U.S. forces repelled an attack by Iraqis using grenades near Najaf, which left as many as several hundred Iraqis dead. There were no reports of American casualties.

With the land war moving closer to the Iraqi capital, there are increasing concerns that Iraqi forces could unleash chemical or biological weapons as a last line of defense. Secretary Rumsfeld has seen what he calls scraps of intelligence indicating the Iraqi military could be preparing for that, after American soldiers on the approach to Baghdad found some Iraqi soldiers equipped with newly-made gas masks.