The bullet-riddled bodies all had their hands and feet bound and showed signs of torture _ hallmarks of death-squad killings, police 1st Lt. Mohamed Khayon said.

The victims ranged in age from between 20 to 50-years-old, he said. Their bodies had been dumped in several neighborhoods of the capital.

Sectarian death squads have killed thousands in recent months and Prime Minister Nouri al-Maliki is coming under increased pressure to find an end to the violence.

Chief U.S. military spokesman Maj. Gen. William B. Caldwell said Monday that there had been a spike in sectarian violence with the onset of Ramadan two weeks ago, though did not provide numbers.

"We anticipated it and we expect it to continue," Caldwell said. "The sectarian tensions in the city are high."

On Tuesday, the body of the brother of a Baghdad police brigadier was found shot dead, tied to a lamppost in Buhriz, 60 kilometers (35 miles) north of the capital, Baqouba police said. Later authorities found the body of another of the brigadier's brothers, also shot, lying in the street.

The bodies of two other shooting victims were found in Khalis, 80 kilometers (50 miles) north of Baghdad, and another was found in Baqouba, police said.

In downtown Amarah, 320 kilometers (200 miles) southeast of Baghdad, a former member of Saddam Hussein's Baath party was gunned down by unidentified assailants, police Capt. Hussein Karim said.

In the northern city of Mosul, a police colonel was killed in a drive-by shooting as he walked through the city, police Col. Abdel-Karim al-Jubouri. A civilian was also killed in the city in a second drive-by shooting, he said.

Meanwhile, authorities updated their casualty figures from the car bombing Monday in Shaab, a mainly Shiite district of Baghdad, that came soon after the evening's iftar meal. Police Capt. Ali al-Obeidi said an additional three people had died, bringing the casualty totals to 13 killed and 46 wounded.