Health Ministry officials said several policemen were among those injured in the attack at a checkpoint leading to Allawi's offices.
"Around 8:45 [a.m.], a man driving an explosives-laden vehicle rammed into the checkpoint guarding the entrance of the street and blew himself up," AFP quoted an unidentified policeman as saying.
The checkpoint was the site of a similar attack on 3 January in which three people were killed, and is the latest in a string of car-bomb attacks ahead of the 30 January national elections, which militants have vowed to disrupt.
The U.S. ambassador to Iraq said American-led troops and Iraqi forces have "elaborate security plans" to defend the elections from militant attacks. Speaking on U.S. television, Ambassador John Negroponte, however, acknowledged there are some "problematic areas" where voting may be difficult.
"I would expect that we will see strong participation by Iraqi voters in the northern and southern parts of this country," Negroponte said. "There will be some problematic areas, particularly in the center, in the Sunni Triangle, especially the provinces of Al-Anbar and Nineveh."
Al-Qaeda ally Abu Musab al-Zarqawi has declared "war" on the elections in an apparent bid to scare voters away from the polls.
(news agencies)For news, background, and analysis on Iraq's historic 30 January elections, see RFE/RL's webpage "Iraq Votes 2005".