The sheiks were associated with the Anbar Salvation Council, which had taken up arms to help drive extremists of al Qaeda in Iraq from the western province of Anbar.
Iraq's prime minister quickly vowed renewed support for Anbar province's tribal leaders after the noontime explosion, which also wounded 27 people and devastated the ground floor lobby of the high-rise Mansour Hotel.
"We are sure that this crime will not weaken the will of Anbar sheiks," Nouri al-Maliki said in a statement.
The attack, in which 21 others were wounded, was just one in a surge of five suicide and other bombings Monday that killed at least 45 people across Iraq.
A man wearing a belt of explosives walked into the Mansour hotel's lobby, approached the group of sheiks meeting there, and detonated his bomb, said a police officer based at the hotel, who spoke on condition of anonymity.
The massive explosion sent concrete crashing down from the ceiling, shattering windows and tore through everything in its path, reports CBS News chief foreign correspondent Lara Logan.
Police identified four tribal leaders killed as former Anbar governor Fassal al-Guood, sheik of the al-Bu Nimir tribe, Sheik Abdul-Azizi al-Fahdawi of the Fahad tribe, Sheik Tariq Saleh al-Assafi and Col. Fadil al-Nimrawi, both of the al-Bu Nimr tribe. Three of al-Guood's guards also were killed, the police officer said.
"It was a great breach of security because there are three checkpoints, one outside and two inside," said hotel worker Saif al-Rubaie, 28, who witnessed the blast and said all the casualties were Iraqis, most employees in the reception area.
The council has been holding meetings in the hotel for months. The deal they reached to join the U.S. military's fight in Anbar province constituted a major blow against the al Qaeda in Iraq-led Sunni insurgency in the region.
The U.S. command has pointed repeatedly to the Anbar group and its opposition to al Qaeda as an example for other tribes to follow elsewhere in Iraq.
Al-Yasiri was also killed in the blast.
In a story
The Mansour, which also houses the Chinese Embassy and is the Baghdad home for a number of Iraqi parliament members, is just a half-mile from the heavily fortified International Zone, where the U.S. Embassy and Iraqi government offices are situated.
A noted Iraqi poet, Rahim al-Maliki, also was killed, said Iraqi Media Net, the government organization on whose television network al-Maliki appeared.
In other developments: