BAGHDAD -- The top U.S. military spokesman in Iraq said Saturday that an Iranian-backed Shiite militia cell was responsible for a market bombing a day earlier that killed at least 13 and left at least 57 injured.
Four men captured in an overnight raid confessed to orchestrating the bombing, said Rear Adm. Gregory Smith.
Also Saturday, the Iraq Interior Ministry said it would bring charges against 31 people detained Monday after a shooting in central Baghdad, for being in the country illegally. The foreign workers were returning from work at the American-run Bucca prison in the south when two Fijians shot in the air to clear traffic and wounded a woman, said the spokesman of the Ministry of Interior, Abdel Karim Khalaf.
The bombing at the al-Ghazl pet market, the most deadly in Baghdad in more than two months, occurred Friday when a bomb loaded with ball bearings and hidden in a birdcage exploded inside the market.
Market bombings typically are conducted by Sunnis, often al Qaida, targeting Shiites. But Friday's attack may be a sign of a new tactic by what Smith described as Iranian funded, supported and trained "special groups." In the past, these same groups have been almost exclusively charged with targeted assassinations and attacks against coalition forces.
"The intent here was to suggest that al Qaida had conducted this operation," Smith said. "And through that kind of intimidation suggest that the people, at least in that area, that what they really need to protect them from this kind of violence are these militia groups."
The bombing was in violation of Muqtada al Sadr's six-month freeze on his vast Mahdi army militia, Smith said.
The accusation comes as followers of the firebrand Shiite cleric are charging that they are the victims of random detentions and human rights violations at the hands of the Iraqi Security Forces in the southern cities of Karbala and Diwaniyah. U.S. officials say Iraqi and coalition forces are going after "criminal elements."
Salah al Obaidi, a spokesman for Sadr, said that more than 1,000 members of the group have been detained in Karbala and Diwaniyah in the last two months. Women have been slapped, kicked and humiliated, he said.
"Until now Jaysh al Mahdi (the Mahdi Army) are under the order to freeze," he said. "Most are following in spite of the campaigns of detentions and violence against them."
Smith warned after the bombing that the lull in violence in Iraq does not mean there is peace. He said coalition forces are continuing to fight both al Qaida and Shiite extremist groups across the capital.
"We still have enemies that we're going after," he said. "We do not assess that we are in a trend of peace, we have a decreasing trend of violence and yesterday's attack is a good example the kind of indiscriminate violence that the enemies of Iraq are willing to play against the people of Iraq."
Monday's shooting incident, in which 45 men -- 33 of them foreigners -- were detained comes in the wake of a Blackwater incident that killed 17 people in mid-September.
Interior Ministry spokesman Abdel Karim Khalaf said two Fijians who are accused of shooting are being investigated and will face criminal charges. The 31 men -- 19 from Nepal, 11 from Sri Lanka and one from India -- entered the country illegally, he said.
It appeared they were returning, hidden under blankets, after completing work at the U.S.-run Bucca prison. Khalaf said the Dubai-based company ALMCO, with headquarters in Baghdad, might also face charges.
U.S. contractors in Iraq have long faced scrutiny for abusing workers from developing nations.
Maj. Brad Leighton, a spokesman with Multi-National Forces Iraq, was unsure if the men were in the country for a U.S. contract.
"It is something we're looking into," he said. "Any allegations of abuse by contractors that are using U.S. dollars we need to look into and we will."
A video circulating on Iraqi cell phones show men covered in blankets in a flatbed truck to disguise their presence. After the shooting local residents crowded around the truck, trying to climb inside to beat the men. Iraqi soldiers are seen beating the men with batons.