Guerillas in Iraq fired at least 10 rockets late Sunday toward the so-called "Green Zone" in Baghdad where the U.S.-led authority has its headquarters.
Sirens went off after at least a few of the rockets landed and exploded inside the heavily-guarded zone.
Reports quoting Iraqi police and a U.S. military officer say there were no casualties from the attack. Officials say the rockets were small and did only minor damage.
Insurgents have attacked the headquarters area many times over the past few months, mostly recently on March 3.
The attacks come less than a day before members of the Iraqi Governing Council and the top U.S. official in Iraq, Paul Bremer, are scheduled to sign Iraq's new interim constitution.
The signing of the document has been delayed twice, first by deadly attacks on Shi'ite Muslim shrines last week and then by the refusal of five Shi'ite Muslim council members to sign.
The five council members raised objections Friday after Iraq's top Shi'ite cleric, Ayatollah Ali al-Sistani, let it be known he believed the constitution gave too much power to minority Kurds in northern IRaq.
Sunday, a senior governing council member said the signing could go ahead after Shi'ite political leaders reached a deal with the Ayatollah. Mowaffaq al-Rubaie, who is also a Shi'ite, did not provide any details of the agreement.
Ayatollah al-Sistani has been playing an increasingly influential role in Iraqi politics as an important religious leader of 60 percent of the country's population.
Mr. Bremer later said on the Fox News Sunday program that he does not know if there will be any changes to the interim constitution before it is signed. The 25 member, U.S.-appointed council gave unanimous approval to the document last week.
U.S. officials consider the interim constitution a key step toward the handover of power to an Iraqi provisional government. Mr. Bremer said today the United States remains committed to handing over power by its stated deadline of June 30, less than four months from now.