Thursday the U.S. military launched an air strike against the so called “safe havens” of al-Qaeda in Iraq.

For 10 minutes the bombers dropped 40,000 pounds of explosives on the southern outskirts of Baghdad.

The attack was part of Operation Phantom Phoenix which was launched Tuesday and was carried by the U.S. and Iraqi troops, the Associated Press reports.

The air attack was followed by a ground one and 12 people were arrested.

According to an Iraqi army officer, the air strike began around 8 a.m. and two houses were discovered where the insurgents tortured their victims. Documents and weapons were confiscated by the soldiers.

The bombs were dropped by two B-1 bombers and four F-16 fighters, according to a statement.

It said: "Thirty-eight bombs were dropped within the first 10 minutes, with a total tonnage of 40,000 pounds."

It is believed that al-Qaeda fighters control Arab Jabour, a Sunni district.

This attack comes a day after nine U.S. soldiers were killed in the northern part of the capital.

Wednesday six American soldiers were killed in Diyala where the insurgents detonated a bomb in a house, according to the New York Times. Four other soldiers were injured and an interpreter was also killed.

In Diyala Sunni fighters are known for using house bombs in order to lure and kill soldiers.

On Tuesday three other American soldiers were killed in Salahuddin Province.

These attacks show that the insurgents still have a great power in the cities dominated by the Sunnis.

The insurgents apparently retreated to Salahuddin, according to top U.S. commander in northern Iraq, Maj. Gen. Mark P. Hertling.

Hertling said Wednesday: "Operational security in Iraq is a problem," saying that the Iraqi army is using unsecured cell phones and radios. "I'm sure there is active leaking of communication."

According to him almost 20-30 insurgents were killed in the first two days of the operation, but the number from Thursday’s attack was unknown.

Last month almost 273 civilians were killed in Diyala. The civilian deaths have dropped in Baghdad from 838 to 182.

Thursday in Baghdad two bombs exploded at a military checkpoint. Two policeman were killed along with a soldier.