Sept. 1 (Bloomberg) -- The United Nations Security Council, meeting in emergency session in New York, unanimously condemned in the ``strongest terms'' terrorist attacks that have killed at least 109 people in Russia in the past week.

Russia sought the meeting after 20 armed men and women wearing explosive belts seized a school in the southern town of Beslan, killing 10 people in the process. They are holding at least 300 hostages, including children, in the country's fourth terrorist attack in eight days.

The 15-member Security Council, calling the hostage-taking a ``heinous act,'' reaffirmed UN determination to combat terrorism that ``constitutes one of the most serious threats to international peace and security.'' Acts of terrorism are ``criminal and unjustifiable, regardless of their motivation,'' the council's statement said

Andrei Denisov, Russia's ambassador to the UN, said the Islambouli Brigades, linked to al-Qaeda and named after the assassin of Egyptian President Anwar Sadat in 1981, seized the school. The group also claimed responsibility for the crashes of two passenger jets Aug. 24 that killed 89 people and a suicide bombing near a Moscow subway station yesterday that killed 10.

UN Secretary General Kofi Annan was ``appalled'' to learn of the Russian hostage-taking, the UN said in a statement. Annan ``calls for the immediate release of the children, their parents and teachers, and condemns in the strongest terms this criminal act directed against the most vulnerable members of society,'' the statement said.

The terrorists at the school threatened to detonate their explosive belts if rescuers attempt to storm the building and said 50 children would be executed if any of the hostage-takers is killed, Itar-Tass said, citing Kazbek Dzantiyev, the head of Northern Ossetia's Interior Ministry.

The fighters are demanding authorities release people arrested as suspects after Chechen rebels raided the neighboring republic of Ingushetia in June.

To contact the reporter of this story: Bill Varner at the United Nations at wvarner@bloomberg.net

Last Updated: September 1, 2004 20:33 EDT