Baghdad, Iraq ? Thursday’s scene of 38 killed by car bomb attacks over a 12-hour period is becoming more prevalent, based on reports gathered in Baghdad from police, military and hospital officials and tracked by AP’s News Research Center.

Car bombers have struck Iraq 479 times in the past year, and a third of the attacks followed the naming of a new Iraqi government two months ago, according to an Associated Press count based on reports from police, military and hospital officials.

The unrelenting attacks, using bombs that can cost as little as a carton of American cigarettes each, have become the most-favored weapon of the government’s most-determined enemies – Islamic extremists.

The toll has been tremendous, according to the AP count: From April 28 through June 23, there were at least 160 vehicle bombings that killed at least 580 people and wounded at least 1,734.

In total, for the year from the handover of sovereignty on June 28, 2004, until June 23, 2005, there were at least 479 car bombs, killing 2,174 people and wounding 5,520.

Graphic breaks down car suicide bombings; two sizes: 2c x 2 7/8 inches; 96 mm x 98 mm; 3c x 5 inches; 146 mm x 127 mm;

Altogether, the AP count shows insurgents have killed at least 1,245 people since new Prime Minister Ibrahim al-Jaafari took over April 28.

Last month was the most violent for Iraqi civilians since the U.S.-led invasion to remove Saddam Hussein from power in March 2003, said Lt. Gen. John R. Vines, commander of the Multinational Corps in Iraq.

There were 77 car bombs in May, killing 317 people and wounding 896.

“The terrorists attack ordinary people, teachers, doctors, newly trained police and others who are assisting the people of Iraq,” U.S. Ambassador Zalmay Khalilzad said.

So far, a series of counterinsurgency sweeps by U.S. and Iraqi forces have not been able to slow the attackers’ pace appreciably.

As Iraqi and U.S. military officials went over plans for a recent sweep in Baghdad, they made a startling discovery: Rather than assembling car bombs outside the capital, insurgents were fitting the cars with explosives at workshops inside the city itself.

That discovery forced officials to scrap the idea of surrounding Baghdad to control all 23 entrances to the city.

Assembling a car bomb costs about the price of a carton of American cigarettes: When the Iraqi government announced the June 7 arrest of a key member of al-Qaida in Iraq, authorities said he was charging just $17 per bomb.