BAGHDAD — Iraq's defense minister promised on Sunday to wage a new crackdown in a volatile province northeast of Baghdad where militants are trying to regroup after being routed from their urban stronghold there last summer.
Suicide attacks have killed more than 20 people in the last three days in Diyala province, a tribal patchwork of Sunni Arabs, Shiites and Kurds that stretches from Baghdad to the border with Iran.
Defense Minister Abdul-Qader al-Obeidi told The Associated Press that preparations had begun for a fresh military operation in the provincial capital, Baqouba, about 35 miles from Baghdad.
"If we succeed in controlling areas of Diyala close to Baghdad, the rate of incidents in Baghdad decreases by 95 percent," al-Obeidi told The Associated Press.
British Prime Minister Gordon Brown, meanwhile, arrived in southern Iraq on a surprise visit to the southern city of Basra, signaling what London hopes will be the transition from a military mission in Iraq to one with a stronger economic component, aimed at reinvigorating a country torn apart by war and years of neglect under Saddam Hussein.
"The great venture that started with all the difficulties we face, that cost causalities, means we have managed now to get Iraq into a far better position," Brown told British troops, who lined the staircases of an airport base to watch his evening arrival. "Not that violence has ended, but we are able to move to provincial Iraqi control and that's thanks to everything you have achieved."
The British plan to hand over security responsibilities for the oil-rich area to the Iraqis in the coming weeks.
Violence has declined sharply in Iraq since June, when the influx of U.S. troops to the capital and its surrounding areas began to gain momentum. Also credited with the decline were the freeze in activities by the Mahdi Army militia, led by the radical Shiite cleric Muqtada al-Sadr, and the decision by tens of thousands of Iraqis _ most of them Sunni Arab _ to join the fight against al-Qaida.
But it has been a constant challenge to subdue extremists in Diyala, which is the eastern gateway to Baghdad. More than two years ago, U.S. forces thought they'd turned the corner and American commanders handed over substantial control of the province to the Iraqi army in August 2005.
Al-Qaida began moving into Diyala in 2006 after losing its sanctuaries in Anbar Province and declared Baqouba as the capital of the Islamic State of Iraq.
Last summer, American troops regained control of Baqouba in a pair of operations, restoring some government services and commerce after months of isolation.
But U.S. officers said at the time they expected the extremists to scatter to hills north of Baqouba and to the city of Muqdadiyah to the east and try to regroup.
Americans have fostered groups of former militants who have switched sides in the fight against al-Qaida. Any gains are hard-won, however: On Friday, a pair of suicide bombings less than 10 miles apart killed at least 23 people _ more than half of them members of the anti-al-Qaida groups.
Rear Adm. Gregory Smith, a U.S. military spokesman, credited intelligence gleaned from Iraqis tired of militant violence, as well as American efforts to track down insurgents' financing, safe houses and bomb-making facilities to the decline in violence around the country. He said Diyala would soon see the same level of improvement.
"We believe there will be a secure, stable Diyala in months to come," Smith said.
Echoing comments by other U.S. officials, Smith said militants have fled the capital and are trying to establish strongholds in vulnerable areas. Baghdad has seen some of the most dramatic improvements. Mortar attacks and sectarian killings, once daily events, have tapered off in recent months.
On Sunday evening, three mortar rounds landed in the fortified Green Zone, city police reported. There was no word on casualties or damage.
But, Smith said, "the enemy has dispersed well away from the cities into the countryside."
About 60 miles south of Baghdad, a roadside bomb struck the convoy carrying the police chief of Babil province, killing him and two of his bodyguards, officials said. Brig. Gen. Qais al-Maamouri, the police chief of Babil's provincial capital of Hillah, was the latest in a series of assassinations against provincial leaders in the mainly Shiite region.
Al-Maamouri was politically independent and had a reputation for leading crackdowns against militia fighters and resisting pressure from religious and political groups to release favored members.
"This criminal act reflects the deep bitterness inside the terrorist groups who failed to destabilize the security of Babil province due to the great work of the late police chief," said the head of the provincial council's security committee, Hassan Watwet.
Watwet said al-Qaida _ largely Iraqi Sunni _ was the prime suspect in al-Maamouri's death.
Sunnis have been turning against al-Qaida in significant numbers and signing up for U.S.-backed security volunteer forces, which Smith said now number 72,000. That represents a sea-change in attitudes among Sunnis, who spearheaded the insurgency against the U.S. and its allies in 2003 while many Shiite politicians worked with the Americans.
But as Shiite militias drove thousands of Sunnis from Baghdad and other areas, many in the Sunni community have reached out to the Americans as protection against the rival sect.
On Sunday, Iraq's Sunni Arab vice president said he supported an agreement for a long-term U.S. presence, signaling a rift between the moderate mainstream of the once-dominant Sunni Arab community and hard-liners on the influence of the United States in Iraq.
"There is no doubt that Iraq needs a strong and honest partner today that has the ability and is ready to help Iraq," Vice President Tariq al-Hashemi said during an address at a regional security conference in Manama, Bahrain. "Yes, I am for an agreement with the United States of America, but this does not mean that Iraq will not be able to sign bilateral agreements with other countries in the world."
President Bush and Iraqi Prime Minister Nouri al-Maliki signed a "declaration of principles" on Nov. 26 that set the foundation for a potential long-term U.S. troop presence in Iraq and confirmed that Washington and Baghdad will hash out an "enduring" relationship.
The agreement between al-Maliki and Bush is based on an August political manifesto, which al-Hashemi signed along with top Shiite and Kurdish leaders, calling for among other things a long-term "strategic partnership" with the United States.
Associated Press writers Qassim Abdul-Zahra, Sinan Salaheddin and Sameer N. Yacoub contributed to this report.