Nearly 40 rounds of aeriel cannon fire were heard across the Iraqi capital on Tuesday. No casualties were reported.
A US military spokesman said five locations from which mortar or rocket attacks had been launched on the coalition's administrative headquarters were targeted in the air raids.
"These targets were struck using an aerial platform with 105 mm cannon fire and 40 mm gunfire," the spokesman said.
"These locations may be abandoned buildings, they may be overgrown. The coalition needs to make sure that its soldiers are safe and cannot be threatened by mortar and rocket attacks," the spokesman added.
Brigadier General Martin Dempsey, commanding general of the US 1st Armoured Division, said the forces had also conducted a raid on the home of a man suspected of storing illegal weapons.
The supect was captured and a dozen rocket-propelled grenade launchers were seized along with two rifles.
"Throughout this operation we are communicating with the Iraqi people to let them know that these combat operations are being executed on their behalf, for it is only in a safe and secure environment that they can achieve the kind of life they deserve," said Dempsey.
The US-led forces have embraced a tough approach in Iraq in recent days, calling in air support and bombarding suspected safe houses and bomb factories.
On 13 November, an AC-130 Hercules gunship was used against a hiding place used by anti-US insurgents in the southern suburb of Dora.
Operation Iron Hammer
The US spokesman said Tuesday's raids were part of Operation Iron Hammer, a massive military offensive launched in and around Baghdad on 12 November.
"It is basically no different than in the previous phases of the operation. It's just the case that it's closer into the centre," he said.
Tikrit has borne the brunt of
In Saddam Hussein's hometown of Tikrit, US forces pounded positions used by fighters for a third consecutive night late on Tuesday in another show of strength.
A platoon positioned itself in a dusty field outside the town, to fire mortar rounds from atop armoured personnel carriers, flanked by combat tanks.
"We are claiming the ground the enemy used in the past," said Lieutenant Colin Crow, the commander of the mortar platoon from the 4th Infantry Division's 1-22 battalion.
"The enemy will think twice about using that terrain again, knowing we can hit it with indirect fire."
Commander defends tactics
Another senior US commander defended the new get-tough tactics Tuesday. "Now it's no holds barred. We use whatever weapons that are necessary to take the fight to the enemy," said Major General Charles Swannack, whose 82nd Airborne Division patrols Al-Anbar province west of the capital, another hotbed of anti-US insurgency.
The general insisted that with the accuracy of modern weaponry, there was minimal danger of collateral damage.
But analysts warned the use of such massive firepower in the heart of the capital risked alienating the very people whose support the coalition professed to seek to win.