A U.S. official says an al-Qaida figure believed to help plan the 2005 subway and bus bombings in London has died.

The intelligence official, who spoke on condition of anonymity, tells VOA that Abu Obaidah al-Masri appears to have died of natural causes some months ago. The official also says Masri died in the Afghan-Pakistan region.

Masri was also suspected in a plot to blow up commercial airliners over the Atlantic Ocean in 2006.

Masri had been reported killed in a missile strike in Pakistan in 2006.

In other news, Afghan officials say seven Taliban insurgents and a policeman were killed in clashes in southern Afghanistan.

The clashes occurred Tuesday in Helmand province and Zabul province.

At least 33 people were killed Tuesday in Afghanistan.

The dead include 17 Afghan road workers killed by Taliban militants in Zabul, and seven insurgents killed in a counter-attack by Afghan and foreign forces. One NATO soldier was killed in a roadside bombing in central Afghanistan.

Some information for this report was provided by AFP, AP and Reuters.