BAQUBA -- A female suicide bomber blew herself up in a crowd of people during a feast in the Iraqi province of Diyala on Monday, killing at least 22 people and wounding 34, a top military officer said.

General Abdel Karim al-Rubaie, the commander of Iraqi troops in Diyala, north of Baghdad, said the attack was in the town of Bala Druz, south of the provincial capital Baquba.

He said the bomber blew herself up at around 7:30 pm (1630 GMT) when people had gathered to break the Ramadan fast at the house of a detainee who was released from the US military prison Camp Bucca on Sunday.

Witnesses from the town told AFP that the bomber attacked as the crowd was finishing dinner and getting ready to leave.

Baquba police Lieutenant Ali Ahmed also confirmed the attack, saying the former detainee, a police officer, had arranged a special dinner on Monday for his friends and relatives when the attack took place.

Ahmed said the released detainee was killed in the blast, along with his father and another senior police officer from Bala Druz. Several policemen were also killed and wounded, he said.

Witnesses said the victims were ferried to the town hospital as well as to Baquba.

Diyala is one of the most dangerous areas of Iraq. Insurgent groups and Al-Qaeda have continued launching attacks there despite a massive military crackdown by US and Iraqi forces.

A number of attacks in Diyala, especially suicide bombings, have been carried out by women.

The latest attack comes hours after two near simultaneous car bombings in central Baghdad killed 12 people and wounded 32, security officials told AFP.

The victims were taken to four city hospitals after the bombs went off within minutes of each other in the central district of Karrada, the officials said.

More than 30 cars were also burned in the explosions, they added.

The attacks took place near a courthouse in the Karrada district at around 11:45 am (0845 GMT).

The latest attacks occurred as US Defense Secretary Robert Gates was in Iraq on a surprise visit and to oversee the handover of US forces' command from General David Petraeus to General Raymond Odierno on Tuesday.

Last week Petraeus told AFP in an interview that he was leaving behind a "significantly improved" Iraq but one that was still vulnerable to attacks by Al-Qaeda.

"A resurgence of Al-Qaeda, return of special groups (Shiite extremist cells) in some form and potential political discord turning into violence on the ground" could erase the security gains achieved in Iraq, Petraeus said.

He said the jihadist group was still not defeated but that "Al-Qaeda has been significantly damaged, degraded and is on the run." But it was still capable of launching "lethal, sensational, dangerous and barbaric attacks."

Al-Qaeda has been blamed by the US military for most of the brutal violence in Iraq since the fall of Saddam Hussein's regime.

The latest attack is one of the biggest in recent months and comes at a time when violence is claimed to be at a four-year low.

A similar attack was also carried out at Ramadan feast in the town of Abu Ghraib on August 24 in which 30 people were killed.

It also comes three days after a suicide bomber blew up an explosives-filled truck near a police station in the Shiite town of Dujail, north of Baghdad, killing 31 people.