BAGHDAD — Iraq's prime minister said Saturday that the government has defeated terrorism in the country, a sign of growing confidence after recent crackdowns against Sunni extremists and Shiite militias.

Prime Minister Nouri al-Maliki launched the crackdowns to extend the authority of the government over areas in Baghdad and elsewhere that have largely been under the control of armed groups since the U.S.-led invasion in 2003.

"They were intending to besiege Baghdad and control it," al-Maliki said. "But thanks to the will of the tribes, security forces, army and all Iraqis, we defeated them."

He was speaking at ceremonies marking the fifth anniversary of the 2003 assassination of Ayatollah Mohammed Baqir al-Hakim, a leading opponent of Saddam Hussein who was killed in a truck bombing in the southern Iraqi city of Najaf after returning from exile in Iran.

Such attacks plagued Iraq following the U.S.-led invasion, but violence in the country has now fallen to its lowest level in four years. The change has been driven by the 2007 buildup of American forces, the Sunni tribal revolt against al-Qaida in Iraq and al-Maliki's crackdowns, among other factors.

"Under the national unity government, the Iraqis have achieved national feats ... that are now lighting the course of our march," said al-Maliki.

Bolstered by this confidence, the prime minister plans to visit the United Arab Emirates today and also Italy and Germany later in the month — apparently hoping improved security at home will pay dividends in greater international support.

Iraq is also enjoying a surge in oil revenue driven by record crude prices and the highest production levels since Saddam's ouster. The government expects to earn a total of $70 billion from oil in 2008 if prices remain high.

Planning to put some of this money to work, the Iraqi government held a groundbreaking ceremony Saturday for a major project to refurbish the main road to the Baghdad airport. The road was once considered one of the most dangerous in the world but has become safer with the decline in violence in the country.

Despite recent gains, daily attacks continue throughout Iraq. Gunmen attacked a police patrol Saturday near Mosul, 225 miles northwest of Baghdad, killing one policeman, police said, speaking on condition of anonymity because they were not authorized to talk to the media.

Also Saturday, one policeman was killed and a passer-by was injured near Nasiriyah, 200 miles southeast of Baghdad, when a bomb attached to the policeman's car exploded, police said, speaking on condition of anonymity for the same reason.

On Friday, one Iraqi citizen was killed and seven were wounded when an explosion occurred in the western Baghdad neighborhood of Yarmouk, said the U.S. military.