Fighting reported at palace in Baghdad
U.S. Army had entered building Monday
CNN's Rula Amin reports that while coalition forces move into Baghdad, Iraq claims it is in control of the city.
BAGHDAD, Iraq (CNN) -- Fighting broke out Tuesday morning at a presidential palace in the heart of Baghdad, sources inside the capital told CNN, with artillery fire focusing on one building in the compound.
The presidential palace -- the largest one in the city -- lies on the west bank of the Tigris River, across the water from the Palestine Hotel. Soldiers from the U.S. Army's 3rd Infantry Division had entered the palace Monday.
The artillery barrage appeared to be focused on one of the buildings in the compound, the sources said. Three or four rockets were fired from the compound as well, but it was not clear who fired them.
Machine gun fire came from the direction of a Baghdad presidential palace about 5 a.m., a correspondent for the Lebanese Broadcasting Corp. said. It's not clear if it was the same palace.
The firing followed several hours of intense mortar and rocket attacks by both sides, CNN correspondent Lisa Rose Weaver reported.
Weaver, who is embedded with the U.S. Army's V Corps, 52nd Air Defense, at Baghdad's international airport west of the city, said the ground vibrated and bright flashes were visible in the direction of the city center for several hours early Tuesday.
U.S. forces used mortars and heavy artillery, and, earlier in the evening, multiple-launch rocket systems, Weaver said.
-- CNN correspondent Nic Robertson contributed to this report
EDITOR'S NOTE: This report was written in accordance with Pentagon ground rules allowing so-called embedded reporting, in which journalists join deployed troops. Among the rules accepted by all participating news organizations is an agreement not to disclose sensitive operational details