Yemeni special forces fired tanks and artillery Tuesday in remote parts of central Yemen, trying to flush out five suspected supporters of Usama bin Laden, according to tribal elders and sources familiar with the details of the operation.

Security officials in Marib province, 100 miles east of the capital, San'a, confirmed special forces were in the Adida region of the province pursuing several men wanted by the government. The officials, who spoke on condition they not be further identified, would not elaborate on why the men were being sought.

Other sources in the region said the bombing came after members of the Adida tribe refused to hand over to authorities at least five men suspected of belonging to bin Laden's Al Qaeda terrorist network.

Bin Laden is the prime suspect in the Sept. 11 terror attacks in the United States. His al-Qaida network also has been blamed in the October 2000 attack on the USS Cole while it was refueling in the Yemeni port of Aden. Seventeen U.S. sailors were killed and 37 injured.

The sources said at least one of the men being sought was a foreign Arab who previously was in Afghanistan.

They said the special forces began bombing after two days of negotiations with the tribe, located in the al-Halsun region of Marib province, ended in a deadlock.

Yemeni security officials refused to comment on the report. Tribal elders confirmed the attack, but would not give a reason for it.

Marib province, home to four powerful tribes with more than 70 branches, has earned a reputation for lawlessness. Since 1990, about 100 foreigners have been kidnapped in Marib, a striking mix of mountains, deserts and cloud-high villages.

Roads are dotted with checkpoints manned by troops or tribesmen, and non-Yemeni visitors to the area are required to travel in convoys escorted by soldiers.

Yemen's government recently stepped up pressure on tribes implicated in or suspected of kidnapping foreigners, who are used as bargaining chips to press for government aid and better living conditions. Most recently, a German businessman was kidnapped Nov. 28 and held by tribesmen in Marib province until being released unharmed on Dec. 8. Only one of the kidnappers was arrested; others are still on the run.