American officials believe top al-Qaeda planner Abu Ubaida al-Masri has died of hepatitis in Pakistan.

Skilled in explosives and coordinating terror attacks, the man is a senior playing in the group’s hierarchy.

The prominent terrorist figure rose quickly through the organisations ranks in 2007 with the second generation of leaders and if reports of his death are true it is a big blow to Al-Qaeda.

However, given his condition it would have allowed time to prepare his successor

London operations

Implicated in the training of London's 7/7 suicide bombers, Al-Masri was in the groups top 10 leaders, organising attacks and perfecting bomb making equipment. He was also named in the plot to blow up transatlantic flights using liquid explosives and is believed to be orchestrating attacks on British troops in Afghanistan. The suspects in the flights plot are currently on trial at Woolwich Crown Court.

The sense is that he is dead," a US official said.