He also forced out Gen. Mohammed Abdullah Shahwani, director of the U.S.-backed and funded Iraqi National Intelligence Service set up by the U.S. Central Intelligence Agency in April 2004.
Shahwani, a Sunni, has close ties to the CIA and apparently fled to the United States following his dismissal. He was a general in Saddam's army, but after the Iraqi dictator's disastrous invasion of Kuwait in 1990 he masterminded an abortive coup against him in 1996.
Shahwani's dismissal strips the Americans of a key ally in Baghdad and leaves Maliki in control of the NIS's 6,000-strong personnel.
The premier also now controls the Ministry of National Security. This is headed by Sheerwan al-Waeli, is a Shiite of Iranian origin who is a member of Maliki's party.
Maliki's government explained the dismissals as "reassignments" in the wake of the bombings, which were a major embarrassment for him ahead of the January elections.
But the sackings were widely perceived as Maliki getting rid of a clutch of generals who were allies of Interior Minister Jawad al-Bolani, a secular Shiite who will be a key Maliki rival in January's polling.
Maliki aides deny that he is conducting an orchestrated purge of his rivals. But his critics say that he's acting alone, without consulting Parliament or senior political leaders, whipping up political rivalries that could erupt into violence as the parliamentary poll approaches.
They believe his next target will be Bolani, widely seen as a close U.S. ally.
Maliki, who not so long ago was seen as a weakling, has also recruited tribal militias that are funded directly by his office.
He has also formed two paramilitary forces, the Baghdad Brigade -- also known as "the Dirty Squad" for its nocturnal sweeps arresting Maliki's critics -- and the Counter-Terrorism Force. Both report directly to him.
Maliki has cemented his control over the nation's security forces by seizing the power of appointing or dismissing army officers, bypassing the chief of staff who should have that authority.
A 30-page report by the U.N. Assistance Mission for Iraq issued in May said that torture of prisoners by Iraqi authorities is widespread and accountability non-existent.
Maliki has declared a nighttime curfew in Baghdad, the easier, his critics say, to conducts mass arrests of his opponents.
The Economist says the U.S.-sponsored judicial system is being overwhelmed, with "some 1,500 people being taken into prisons every month as the Americans empty their own jails. … Moreover, sentencing is getting harsher, with more people sentenced to death."
The Journalistic Freedom Observatory, an Iraqi lobby group, says that with the Americans on the way out, "the government is opening the door once again to dictatorship. This is the return of repression."