Tripoli/Moscow, Aug 23 (IANS): Libyan leader Muammar Gaddafi's elder son, Mohammad, has escaped, Al Jazeera said. He was captured by the rebels earlier Monday.

Mohammad, who was arrested in his house during an interview with Al Jazeera, fled with the help of one of the rebels, RIA Novosti reported.

Two other Gaddafi's sons, Saif al-Islam and Saadi, were arrested earlier.

Fresh clashes between the rebel troops and security forces loyal to Gaddafi erupted Sunday on the outskirts of the Libyan capital, Tripoli.

Fighting was still raging Monday evening around Gaddafi's compound in Tripoli but the whereabouts of the Libyan leader, who ruled the oil-rich country for over 40 years after seizing power in a bloodless coup in 1969, were still unknown.

Libyan rebels Monday tightened their grip on Tripoli with the capture of three of Muammar Gaddafi's sons and a hunt was on for the 68-year-old Libyan leader.

Rebel commanders said they have taken control of about 80 percent of the city following an overnight assault on the capital, BBC reported.

World leaders have urged Gaddafi to step down, and Egypt has recognised the rebels as the legitimate government.

Libyans seeking Gaddafi's ouster rejoiced Sunday after news that two of the ruler's sons -- Saif al-Islam and Saadi -- had been arrested by opposition forces.

On Monday, a third Gaddafi son, Mohammed, was also taken into custody, the broadcaster said.