Baghdad ? Two more tribal leaders were assassinated in Baghdad on Tuesday, a day after a bombing at a hotel downtown killed 13 people, including members of a Sunni Muslim council that recently had allied with U.S. forces fighting Sunni insurgents linked to al-Qaida.

Sheik Hamid Abdul Farhan al-Shujairi, a Sunni, was shot in a mainly Sunni area of Baghdad, police said. He reportedly had attended a conference several weeks ago supporting the government and fighting insurgents.

Gunmen murdered Hamid Abid Sarhan al-Shjiri, the sheik of the mixed Sunni-Shiite Shijirat tribe, while he sat in his car in the capital’s southern al-Saidiyah neighborhood.

The deaths came as Iraqi authorities tried to determine how a bomber made it through a tight security cordon Monday at the Mansour Hotel and detonated explosives that killed at least six members of the Anbar Salvation Council, a Sunni tribal coalition that had been cooperating with U.S. and Iraqi government forces.

Among the dead was Sheik Fassal al-Guood, a council leader and former governor of Anbar province who had long advocated working with the United States before the U.S. military finally embraced his group late last year.

An al-Qaida-affiliated group in Egypt claimed responsibility for the blast, which devastated the Mansour’s lobby, where al-Guood and other Sunnis had gathered to meet with Shiite Muslim tribal leaders. Witnesses said they thought that a suicide bomber had set off the charge, though the scale of the destruction suggested that the bomber might have had assistance.

U.S. troops don’t protect the Mansour, which is outside the fortified Green Zone. The Chinese Embassy and the offices of some news organizations, including CBS News, are housed at the hotel.

Arrest warrant issued

Also on Tuesday, Iraqi authorities issued an arrest warrant for the minister of culture, a Sunni, on charges that he had ordered an assassination attempt against a more moderate Sunni politician more than two years ago.

Culture Minister Asad Kamal al-Hashimi wasn’t at home when police raided his house, and his whereabouts were unknown. His party, the hard-line Congress of the People of Iraq, condemned the warrant and accused the Shiite-dominated government of “fabricating lies to exclude Sunni politicians and officials from the Iraqi arena.”

Al-Hashimi is the first full member of the Cabinet to be accused of directing violence in Iraq, although Iraqi authorities have arrested other senior officials, including the deputy health minister, who was linked to radical cleric Muqtada al-Sadr’s Shiite militiamen.

Authorities said two suspected militants had named al-Hashimi as the mastermind of an ambush on Feb. 8, 2005, against then-parliamentary candidate Mithal al-Alusi. Al-Alusi, who had won notoriety in 2004 for traveling to a security conference in Israel, escaped unharmed, but two of his sons were killed.