BAGHDAD - Iraq's government is grateful to U.S.-allied Sunni fighters but won't allow them to keep their weapons indefinitely, the prime minister said Saturday, hinting at a more intense crackdown on the Sunni groups.

In recent weeks, the Shiite-dominated government of Prime Minister Nouri al-Maliki has gone after Sunni fighters despite their alliances with the Americans. Some leaders have been arrested, while scores of others have been disarmed and banned from manning checkpoints except alongside security forces.

Al-Maliki's government has mixed feelings about Sunni tribes that rose up against al-Qaida in Iraq, starting in 2007, and joined the Americans in the fight against the terror network.

The groups, known as Awakening Councils, Sons of Iraq and Popular Committees, have helped rout out al-Qaida in Iraq in some parts of the country. But Shiite leaders fear that the Sunnis' switch of allegiance is just a tactic and that they could one day turn their weapons against the Shiite majority.

The U.S., which put many of the Sunni fighters on its payroll, has urged al-Maliki to incorporate them into his security forces, but the government has been slow to do so.

In a speech to Shiite tribal leaders in Baghdad on Saturday, al-Maliki mixed praise for the Sunni fighters with a warning.

He said armed groups, alongside security forces, were tolerated for a limited period because their weapons were "aimed at the chests of the terrorists."

The Sunni fighters "deserve our gratitude and the inclusion [into the security forces] because we adhere to a policy that there are no arms but the arms of the government," he said.

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