BAGHDAD — Faster than anyone expected, barely a month after the last U.S. troops left, Iraq's government appears to be coming apart, prompting fears that the country is headed for another round of sectarian strife.

Prime Minister Nouri al Maliki, a Shiite Muslim, is driving to consolidate control and sideline more secular politicians in a battle that increasingly appears to be a fight to the finish in which there can be no compromise.

Barham Salih, the widely admired prime minister of the autonomous Kurdish region in the north, said the infighting is "tearing the country apart." Preemption is the name of the game.

"The motto is: 'I'll have him for lunch before they have me for dinner'," he said during an interview in his office in Irbil.

The downhill spiral takes a new turn every week, sometimes daily. Responding to a boycott by his Sunni partners in the power-sharing government, Maliki last week locked them out of their jobs, ordering ministries to bar their doors to cabinet officers, even though they still have a mandate from the Iraqi parliament.

A day later, the Iraqiya bloc headed by secular Shiite Ayad Allawi, which has 94 seats in the 325-seat parliament, said that if Maliki did not agree to curbs on his power, he should be replaced, either in new elections or by a vote of Maliki's Shiite backers in parliament.

Iraqi politics today is a constellation of clashes, many in plain view, but others below the surface. "It's just one-fifth of the iceberg that we are seeing," said Tahseen Shekhli, an adviser to the prime minister. "The more dangerous disputes are still hidden."

What's visible is disturbing enough.

The country's vice-president, a Sunni, fled last month to Kurdistan, where he's safe from Iraqi justice authorities seeking his arrest on allegations that he directed hit squads against prominent Shiites. Maliki has attempted to oust the deputy prime minister, also a Sunni, but Sunni and Kurdish legislators refuse to hold a vote, paralyzing the parliament.

Maliki has sent troops and tanks into the streets of the Green Zone, where most prominent politicians live, and warned top leaders that he is keeping "files" on them.

Allawi, who's been a no-show at parliament and seems to be abroad more often than in Iraq, says that Maliki has arrested more than 1,000 political opponents on the pretext of preventing a coup by members and supporters of the Baath party of ousted dictator Saddam Hussein.

All is not well within Maliki's bloc, either, which is able to control the parliament with 159 votes.

Supporters of radical Shiite cleric Muqtada al Sadr, who hold 40 of those seats, abstained in protest when they were asked to remove Sunni ministers from their jobs, and they're outraged by Maliki's courting of Shiite extremists who are rivals to the Sadrists.

In the midst of the political squabbling, insurgents, very possibly Al Qaida, have carried out terror assaults, killing at least 250 civilians in Baghdad and other cities in the time since U.S. forces left, giving the country a security scare.

The Obama administration, which trumpeted the U.S. troop withdrawal as the fulfillment of a campaign promise, views the internal conflict as a real crisis and a big problem for future relations.

The United States has "repeatedly" told Maliki and other political leaders that "our relationship, all the things we want to do" depend on "a resolution through constitutional means," a State Department official said. The official asked not to be further identified because of the sensitivity of the subject.