George Habash, the Palestinian leader and a longtime rival of Yasser Arafat, the former Palestinian president, has died in Jordan, aged 80.
Habash, who passed away on Saturday, founded the Popular Front for the Liberation of Palestine (PFLP), which carried out the hijackings of several aircraft in the 1970s.
â€œHe had a severe heart attack and he died instantly,â€ Leila Khaled, a member of the Palestine National Council and a leading member of the PLFP, said.
Khaled spoke by telephone from Jordan Hospital in Amman, where she said Habash died at 8:15pm (1815GMT) on Saturday.
In Damascus, Maher al-Taher, the PFLPâ€™s spokesman, confirmed Habashâ€™s death. Habash had been living in Amman since 1992, he said.
The office of Mahmoud Abbas, the Palestinian president, has declared a three-day mourning period for Habash.
In Gaza, Ismail Haniya, the Hamas leader, said Habash â€œspent his life defending Palestineâ€.
Habash founded the PFLP, which promoted armed resistance, in December 1967 – six months after the war in which Israel seized east Jerusalem, the West Bank and the Gaza Strip.
The group was responsible for the hijackings of four Western airliners over the US, Europe, the Far East and the Gulf in 1970.
The aircraft were blown up in the Middle East after their passengers and crews had disembarked.
Born into a wealthy Christian Arab family, Habash became a refugee after the 1948 creation of Israel.
He graduated in 1951 from the American University of Beirut, going on to become a paediatrician.
He was a co-founder of Harakat Al Qawmeyon Al Arab, a pan-Arab nationalist movement founded in 1952 that has had a profound impact on Palestinian and Arab political thought.
He later espoused Marxism and emerged as an internationally recognised leader of the Palestinian liberation movement and the broader struggle for political and social justice.
For many Arabs, he was one of the few leaders who embodied the Palestinian cause.
His PFLP movement favoured armed struggle to establish a Palestinian state and opposed Arafat, breaking completely with him over the signing of the Oslo Peace Accords in 1993.
However, he wrote one of the most moving eulogies for Arafat.
Habash resigned as secretary-general of the PFLP in 2000, citing health reasons.