At least two rockets slammed into Iraq's oil ministry shortly after seven o'clock Friday morning, sending thick black smoke into the sky.

Minutes later, rockets hit the heavily guarded Palestine and Sheraton hotels simultaneously. The two 20-story hotels stand side-by-side on the east bank of the Tigris River and are home to a large number of U.S. officials and major American news organizations.

An Iraqi policeman, Ahmed Ouda Nasir, says he saw the upper floors windows of the Palestine Hotel explode, as several rockets hit the building.

Mr. Nasir says he was standing near the front entrance of the hotel when he noticed that a donkey cart had been left on the street, close to the building. Mr. Nasir says he was about to examine it when rockets exploded out of the cart and slammed into the hotel.

The U.S. military confirms it has found multiple rocket launchers on donkey carts near the oil ministry and the two hotels, suggesting the attacks had some degree of planning and coordination.

There were no injuries at the oil ministry, which was closed Friday, the Muslim day of prayer. But witnesses say at least one person staying at the Palestine Hotel suffered a serious head injury.

Elsewhere in Baghdad, Iraqi police on Friday discovered a launcher fitted with 30 rockets, abandoned on a street near the Italian embassy. It is not known whether the embassy was the intended target.

In recent months, insurgents across Iraq have mounted increasingly bold attacks on coalition troops, foreign organizations and Iraqis working with the U.S. led administration.