Who is Abu Nidal?

Abu Nidal, the radical Palestinian guerrilla leader linked to last Friday's attacks at Rome and Vienna airports, is one of the world's most wanted guerrillas. A surviving gunmen in Rome told an investigating magistrate that he belonged to a Palestinian suicide squad linked to Abu Nidal which planned more attacks in Europe. And a caller to a Spanish radio station also said Abu Nidal followers were responsible for the attacks.

Abu Nidal, whose real name is Sabri al-Banna (his nom de guerre means ``Father of the Struggle''), broke with Palestine Liberation Organization chairman Yasser Arafat's Al-Fatah guerrilla group in 1974 and formed the Fatah Revolutionary Council, based first in Baghdad and later in Syria.

Now believed to be living in Libya, he has been accused of masterminding last month's hijack of an EgyptAir Boeing 727 to Malta in which 60 people died.

His group claimed responsibility for shooting the Israeli ambassador to London in 1982, which sparked Israel's invasion of Lebanon in June of that year.

He was the PLO's main representative in Baghdad until the PLO expelled him in 1974 and sentenced him to death for plotting to kill Mr. Arafat.

Firmly opposed to Arafat's shift toward seeking a negotiated Middle East settlement, Abu Nidal's guerrillas were blamed by European authorities for killing PLO representatives in London, Paris, Brussels, Madrid and Rome in the 1970s.