DUBAI: A U.S. drone attack appears to have killed a relative of al Qaeda's leader in Yemen, where militants have exploited opposition to veteran ruler Ali Abdullah Saleh this year to establish a firmer foothold.

Residents in the town of Zinjibar in the southern province of Abyan said a drone had attacked a district of the town controlled by militants on Thursday evening.

They said they saw the body of a man killed in the strike who was named Abdulrahman al-Wuhayshi.

A security source said the man was a relative of Nasser al-Wuhayshi, a Yemeni who leads al Qaeda in the Arabian Peninsula, the joint Saudi-Yemeni branch of al Qaeda. Wuhayshi was once Osama bin Laden's personal aide in Afghanistan.

A local official confirmed there had been a drone attack but said he did not know who had been targeted.

There was no word of any death of a leading militant on Islamist websites where al Qaeda often announces such news.

Abyan province saw an upsurge in fighting this week between government forces and Islamists, in which about 50 people were killed, mostly on the Islamist side, officials said.

An opposition-led government has been set up in Yemen after Saleh agreed last month to transfer authority to his deputy president ahead of presidential elections in February.

But violence has continued as protesters demand that the government is purged of members of Saleh's family and that Saleh face trial for the violence of the past 12 months.

Saudi Arabia and Western powers, who backed Saleh for years as a bulwark against al Qaeda, fear that militants could strengthen their hand in the tense transition period.

Thousands of protesters set off on a 200 km (125 mile) march from the city of Taiz to Sanaa earlier this week to denounce the new government since it will spare Saleh from prosecution.

The marchers are expected to arrive in the capital on Saturday and camp outside on Friday.

Ali al-Emad, a protest organiser in Sanaa, said pro-government thugs had attacked two cars and loudspeakers of protesters in Sanaa who intend to meet the Taiz marchers when they arrive at the edge of the city.