By Suadad al-Salhy
BAGHDAD (Reuters) - Anti-U.S. cleric Moqtada al-Sadr's Mehdi Army has spawned dozens of renegade splinter groups which frequently assassinate Iraqi officials on behalf of foreign sponsors, Sadrist and security officials say.
The Mehdi Army, which fought against U.S. troops after the 2003 invasion of Iraq, has fractured into small, well-trained and well-armed criminal gangs involved in contract killings, kidnapping and extortion from homeowners, businessmen and government agencies, particularly in Baghdad.
A popular Shi'ite cleric who leads the militia as well as his own political bloc, Sadr has repudiated the splinter groups, describing them as "murderers" and "criminals," and has called on Iraqi security forces and tribes to expel them.
"They have turned into mercenary groups which have no ideology or specific agenda. They are more like contract killers," said Major-General Hassan al-Baidhani, chief of staff for Baghdad's security operations command.
"They have no connection with Sadr offices or Moqtada al-Sadr," Baidhani said.
Sadr disarmed his militia after Shi'ite Prime Minister Nuri al-Maliki's troops -- backed by American forces -- defeated it in Baghdad and southern cities in 2008.
His Sadrist movement has become a force in mainstream politics. But many of his fighters have had a difficult time adjusting to normal life, sources said.
"They are accustomed to the killing and the power and can't let go," said Kamal, a Mehdi Army leader who asked that his surname not be used because of his militant past.
At the height of Iraq's 2006-2007 sectarian slaughter, the Mehdi Army was seen by Washington as one of the biggest threats to security with its young fighters toting rocket launchers and battling U.S. and Iraqi troops in the streets.
Violence has fallen sharply since then, and the Sunni Islamist al Qaeda group is routinely blamed for attacks.
Security forces have made strides against the insurgency, but militants have stepped up attacks to destabilize the government as U.S. troops prepare to leave by the end of the year, more than eight years after toppling Saddam Hussein.
THE KILLING BUSINESS
Both Shi'ite and Sunni groups carry out killings but a recent spree targeting police and army officers in Baghdad was the work of Shi'ite militias concerned about a return of Saddam's outlawed Baath party, security officials told Reuters.
Iraqi officials say the militias are well-trained and have access to government cars, badges and other equipment.
"The Interior Ministry, Defense Ministry and National Security Ministry are infiltrated completely by the leaders of these groups," said a senior police officer who declined to be named. "Unfortunately, they can catch anyone in Baghdad."
Officials said the splinter groups have teams for surveying and catching targets, killing and documentation. Drive-by hit squads consist of a driver, a passenger-seat sniper and a gunman to protect the shooter.
Baidhani said the assassination squads must prove their kills. The documentation groups are responsible for video of the crime scene and the victim's body before disposal.
"This has become a business earning cash," he said.
THE HAND OF IRAN
Washington has 46,000 troops in Iraq and Iraqi leaders are debating the divisive question of whether to ask some to stay.
June was the deadliest month for U.S. forces in three years. U.S. officials blame Iranian-backed Shi'ite militias.
James Jeffrey, the U.S. Ambassador to Iraq, said recently that Iran's Islamic Revolutionary Guards Corps and its Qods force special operations unit were supplying "significantly more lethal weapons systems" to some Iraqi militias.
Tehran has denied such accusations in the past.
While the well-known Asaib al-Haq and Kata'ib Hizballah are the biggest Mehdi Army splinter groups, dozens of others have appeared, working as mercenaries and killing for sponsors inside and outside Iraq, Sadrist and Iraqi security officials said.
"They have become an intelligence tool employed by Iran to terminate its opponents in Iraq," said a senior Sadrist leader close to Moqtada al-Sadr who asked not to be identified.
Sadrist sources said the groups are funded and trained by Iran and use weapons similar to those of the Iraqi security forces -- M16 rifles and Glock pistols.
"The problem ... is that Sayed Moqtada does not order their termination. He fears the (rebellion) that will be created between the sons of the same sect," the Sadrist leader said.
"Also he does not want to collide with the Iranians now. The (Sadrist) movement still needs them," he said.
SADR CITY TIME BOMB
Sadr recently said the Mehdi Army militia would remain "frozen" even if U.S. troops stayed beyond the year-end deadline, due to an increase in "evil acts" among those "who claim they belong to the Mehdi Army."
He was pointing at the vast Shi'ite slum of Sadr City in east Baghdad, bastion of the Mehdi Army and its splinters. Most of the hit squad members live and work there, officials say.
Last month, Mehdi Army factions fought gun battles in Sadr City. Sadrist and security officials said most such clashes result from turf wars between groups extorting contractors, government agencies and home- and shop-owners who are forced to pay millions of dinars to preserve their lives and property.
"Sadr City has turned into a time bomb that could blow up at any minute," the Sadrist leader said.
(Editing by Jim Loney and Alistair Lyon)