A senior Egyptian al-Qaeda member and former aide to Osama Bin Laden was reportedly killed in an American air strike in northwestern Syria, a monitoring group and relatives confirmed.

The Britain-based Syrian Observatory for Human Rights said Rifai Ahmad Taha, 60, who was fighting in Syria, died in a US drone strike on Tuesday in Syria's Idlib province.

In Egypt, a relative said Taha's wife and brother received confirmation about his death and dozens of members of armed groups were paying condolences on Friday to the family. The relative spoke on condition of anonymity to The Associated Press news agency.

Al-Qaeda's Osama bin Laden killed

However, in Washington, Department of Defense spokesman Matthew Allen said officials couldn't confirm Taha's death.

"I can confirm that the US struck a vehicle killing several AQ militants," said Allen, using an acronym to refer to al-Qaeda.

"The results of this strike are still being assessed."

Before joining al-Qaeda, Taha was a top figure in Egypt's armed group Gamaa Islamiya, which massacred 58 foreign tourists in the ancient Egyptian city of Luxor in 1997.

Taha was jailed in 2001 in Egypt under the rule of then-president Hosni Mubarak after being detained in Syria and handed over to Cairo. He was released after Mubarak was removed from power in 2011.

He was also involved in plotting an assassination attempt against Mubarak during a visit to Ethiopia in 1995. The former Egyptian president was not harmed when his convoy was hit by gunfire.

In the early 1980s, Taha spent five years in jail after the 1981 assassination of Egyptian president Anwar Sadat.

Osama bin Laden formed al-Qaeda after fighting with the mujahidin against the Soviet Union in Afghanistan during the 1980s. The group is blamed for carrying out the September 11 attacks on the United States that killed about 3,000 people in 2001.

Bin Laden was killed in a raid in Pakistan by US special forces in May 2011.