Suicide bombings like Monday's are rare in oil-rich Basra, where several international oil companies are developing some of the country's prized oil fields to bring in the sorely needed petrodollars for postwar reconstruction.
Provincial police chief Brig. Faisal al-Ebadi said the guards opened fire at the bomber's car after he failed to stop. The attacker's vehicle crashed through the gate a few yards (meters) into the police compound in the city's central al-Ashar district before blowing it up.
Three policemen and two civilians were killed and 23 people were injured in the attack, which occurred during the morning rush hour, al-Ebadi added.
The blast leveled the wall around the police compound, which houses the rapid reaction unit and general inspector's office, blowing out the windows and destroying several vehicles parked in front. Police and rescuers were seen examining the debris that littered the pavement with broken glasses.
A health official, speaking on condition of anonymity because he was not authorized to speak to the media, confirmed the toll.
The last major attack in Basra took place last March when a roadside bomb missed a passing U.S. military patrol but killed six Iraqis and wounded 12 others.
Basra is Iraq's second-largest province and home to about 70 percent of the country's proven oil reserves of 143.1 billion barrels. It is Iraq's only outlet to the sea and is the hub for most of Iraq's oil exports of nearly 2.225 million barrels a day.
The provincial capital, also called Basra, is 340 miles (550 kilometers) southeast of Baghdad.
While violence in Iraq is well below what it was during the intense Shiite-Sunni sectarian fighting in 2006 and 2007, militants are again stepping up deadly attacks around the country.
Iraq's government and political factions are mulling whether to ask that some American forces remain in the country beyond the Dec. 31 deadline for all U.S. troops to withdraw after more than eight years. There are mounting security concerns what will happen when the 47,000 U.S. troops withdraw.