SANAA - At least 20 people were killed late Saturday when an al-Qaida suicide bomber targeted a gathering of pro-government tribesmen in the country's southern province of Abyan, a police official told Xinhua.

"An al-Qaida bomber detonated his concealed explosive belt among the crowd at a funeral in Jaar town in Abyan on Saturday night, killing at least 20 people and injuring dozens of others," the official told Xinhua on condition of anonymity.

He said that "Abdulatif al-Saeed, the leader of the tribal fighters who supported the government troops in the fighting against al-Qaida over the past months, was killed in the bombing attack."

Dozens of people were wounded in the attack, which officials described as the worst assault in Abyan since the Yemeni government troops seized strongholds of the terrorists two months ago.

The deadly attack took place in less than one hour after a Yemeni-U.S. coordinated airstrike killed four al-Qaida militants in the southeastern province of Hadramout.

Backed by the United States, the Yemeni government waged a month-long intensive offensive in May against the militants of al- Qaida, known locally as Ansar al-Sharia (Partisans of Islamic Law), forcing them out of strongholds they had controlled for nearly a year.

At least 20 cadets were killed and 20 others injured in a suicide bombing at the police academy in Yemen's capital Sanaa on July 11 despite tight security around key local and foreign installations to prevent terrorist attacks.

Saturday's deadly bombing was the third in the past two months in Yemen, after the deadliest-ever attack on a military parade rehearsal in May, which killed about 100 central security forces in the capital, casting shadows over Yemen's peaceful transition process after more than 18 months of unrest.

Combating al-Qaida militants in the restive south is one of the challenges confronting Yemeni President Abd-Rabbu Mansour Hadi, who has promised to restore security and uproot the country's branch of al-Qaida.