At least 10 people were killed and dozens wounded when Yemeni security officials opened fire on protesters in Sana'a.

Medical officials and witnesses say the shootings took place Saturday as thousands of demonstrators gathered to renew calls for President Ali Abdullah Saleh to leave office.

Witnesses say some of the unrest took place in areas of the capital that have been strongholds for opposition tribal leaders and loyalists of Ali Mohsen al-Ahmar, a Yemeni general who joined the opposition.

In a separate development, an airstrike in southeastern Yemen has killed at least seven suspected al-Qaida militants, including a son of slain U.S.-born cleric Anwar al-Awlaki.

Tribal leaders say Abdul Rahman al-Awlaki was killed Friday, along with four other members of the Awlaki clan, in the suspected U.S. strike in Shabwa province.

Earlier, Yemen's Defense Ministry said the media chief for al-Qaida's Yemen branch, Egyptian-born Ibrahim al-Bana, also died in the strike.

Hours later, in an apparent revenge attack, suspected militants blew up a gas pipeline. Officials say operations were halted at a gas supply terminal as a result.

The elder Awlaki was killed in a U.S. drone strike in September. He was wanted in both the United States and Yemen for his suspected role in terrorist attacks and ties to the Yemen-based group al-Qaida in the Arabian Peninsula.