May 4 (Bloomberg) -- At least 50 people were killed today and many others wounded in a suicide bombing in Iraq's northern Kurdish city of Arbil, the U.S. military said. The attack is one of the worst since the country's Jan. 30 National Assembly vote.

The bomb went off as people were queuing outside a police recruitment center located in an office of the Kurdistan Democratic Party, U.S. military spokesman Captain Mark Walter said in a telephone interview from Mosul, citing initial figures obtained by a U.S. civil liaison officer in Arbil. As many as 150 were injured, AP cited al-Arabiya as saying.

An unidentified police official told al-Jazeera that 60 had died, while a doctor said 45 were killed, the Qatar-based network reported. Al-Jazeera showed ambulances and taxis taking victims from the scene and said the death toll is expected to rise because many were seriously wounded.

The assault is the worst terror attack in Iraq since the poll after a bombing outside a medical clinic on Feb. 28 in Hillah, 60 miles (100 kilometers) south of Baghdad that killed 120 people and injured 135.

Today's bombing brings to about 200 the number of people killed in attacks since the approval last week of a partial list of cabinet members Iraq's new government, AP said.

Ansar al-Sunna, a terrorist group that is linked to al- Qaeda, claimed responsibility for the bombing, saying in a statement posted on the Internet that it was carried out in revenge for the Kurdish alliance with U.S. forces, the Associated Press reported.

Cabinet Sworn In

Prime Minister Ibrahim al-Jaafari and his 29 ministers were sworn in yesterday. Six posts, including the oil and defense ministries, remain unfilled because of differences within the minority Sunni Arab community on the post of defense minister, promised to them to correct an imbalance of power following a low Sunni turnout in the Jan. 30 poll, al-Jaafari said.

The explosion in Arbil, 217 miles (350 kilometers) north of the capital, Baghdad, occurred at 9 a.m. local time between the Sheraton and Zeytoun hotels, damaging nearby buildings and cars, the Patriotic Union of Kurdistan said on its Web site.

Insurgents have frequently targeted police and army recruits, as well as members of Iraq's security forces, all of whom they accuse of being collaborators with U.S.-led forces. Supporters of the ousted Sunni-dominated regime of Saddam Hussein and followers of al-Qaeda are trying to undermine reconstruction in the country and force a withdrawal of coalition forces.

An unidentified doctor at Arbil's al-Jumhouri hospital, one of three medical centers treating casualties from today's blast, told al-Jazeera that a large number of the patients are suffering from burns and shrapnel wounds, and that a 10-year-old child is among bystanders who were injured.

Kurdish Factions

Kurdistan, the Kurdish-controlled northern provinces of Sulaymaniyah, Arbil and Dohuk, became autonomous after the 1991 Gulf War and has been ruled since 1992 by elected officials. Kurds represent 15 to 20 percent of Iraq's population.

``I really do believe this tragedy is an isolated incident,'' Bayan Sami Abdul Rahman, a U.K. representative to the Kurdistan Regional Government, said in a telephone interview. ``Kurdistan will remain much safer than the rest of Iraq because it has had a democracy for 14-15 years and because it's protected by homegrown, trusted defense forces -- the Peshmerga,'' Abdul Rahman said.

The last major attack in Kurdistan was January 2004, when two suicide bombings in Arbil killed more than 100 people, in what was then the deadliest attack since the March 2003 U.S.-led invasion to topple Saddam Hussein, Agence France-Presse said.

The Kurdistan Democratic Party, headed by Massoud Barzani, and the Patriotic Union of Kurdistan, led by Iraqi President Jalal Talabani, are Iraq's two main Kurdish factions. Talabani and Barzani ran separate governments in Kurdistan, one in Sulaymaniyah and the other in Arbil, until this April when they merged administrations.

Regional Capital

Arbil is soon to become the regional capital of Kurdistan, and will house its administrative, governmental and parliamentary buildings, the Kurdistan Regional Government said.

``Attacks like this will in no way break the resolve of either the Kurdish people or the vast majority of people in Iraq to see a peaceful, democratic and truly representative government in our country,'' Bayan Sami Abdul Rahman said.

Earlier this month, one of Hussein's relatives was arrested by Iraqi forces after being accused of supporting the insurgency, Iraq's government said today in an e-mailed statement. Aymen Sabawi was apprehended north of Hussein's hometown, Tikrit, the government said. He is a son of Hussein's half-brother Sabawi Ibrahim al-Hassan al-Tikriti, it said.

Sabawi and his brothers aided insurgents by providing financial support, weapons and explosives, the government said, without elaborating. Their father, who was captured in February, was No. 36 on the U.S. list of the 55 most-wanted people in Iraq. He'll be prosecuted for torture and conducting terrorist activities, the Iraqi prime minister's office said at the time.

Separately, Japan plans to withdraw its 600 soldiers from their non-combat mission in Iraq by December, Kyodo News reported today, citing unidentified government officials.

The withdrawal is meant to coincide with democratic elections scheduled to be held by December 15, and the United Nations mandate for multinational-force operations in the country ends at the end of the year.

Meanwhile, Denmark's opposition parties will back a government proposal to keep Danish troops in Iraq until February 1 next year.

To contact the reporter on this story: Caroline Alexander in London at calexander1@bloomberg.net

Last Updated: May 4, 2005 12:01 EDT