Lebanese Premier Rashid Karami was assassinated today when a bomb exploded in an attache case on his lap aboard a military helicopter.
Injured in the explosion were Interior Minister Abdullah Rassi and three of the other 12 aides and crewmen on the aircraft.
Sources at the army command said the blast was a "premeditated assassination by a time bomb."
A man identifying himself only as Capt. Hammoud claimed responsibility for Karami's assassination on behalf of the previously unknown Lebanese Secret Army. The caller, who spoke in Arabic, made the claim in a call to a Western news agency in Beirut.
The 65-year-old Sunni Muslim had been Lebanon's longest-serving premier minister, holding office 10 times in 32 years. He was backed by Syria, the main power broker in Lebanon.
Karami was the most prominent Lebanese official assassinated since a 1982 bombing killed President-elect Bashir Gemayel, the brother of President Amin Gemayel.
Karami's helicopter was halfway between his summer residence in Bqaa Safrine and Beirut, 60 miles to the south, when the explosion ripped through the aircraft.
An army major took over from the wounded pilot and landed the crippled Puma helicopter at the Halat military air base. The victims were rushed to a hospital in Byblos, 19 miles north of Beirut.
Radio reports said Karami died on the operating table.
Gemayel, a Maronite Catholic, ordered an investigation. A palace source said Gemayel personally arranged for Karami's body to be sent to his hometown, the northern port of Tripoli.
Radio stations said shops closed and business came to a standstill in Tripoli after Karami's murder was announced. Students walked out of classes and demonstrated in the streets, radio reports said.
Syria denounced the assassination as a "major tragedy and an odious crime."
The right-wing Christian Lebanese Forces, which opposed Karami bitterly for his pro-Syrian leanings, also denounced the assassination.
Karami was premier when Lebanon's civil war broke out in 1975. He said last month that he was resigning because of the failure of his half-Christian, half-Muslim Cabinet to deal with the country's economic crisis, which stemmed from the war.