A Russian airliner en route from Tel Aviv to Siberia has crashed into the Black Sea with 66 passengers and 11 crew on board. Russian officials are downplaying suggestions that the plane may have been shot down accidentally by Ukrainian military forces conducting exercises in the area. Siberia Airlines flight 1812 from Tel Aviv to the city of Novosibirsk went down in the Black Sea some 185 kilometers southwest of Sochi. The report initially raised fears of a possible terrorist attack, but U.S. officials in Washington say the Ukrainian military was holding exercises in the area and may have accidentally shot down the plane with a missile.

At a press conference following a meeting with visiting British Prime Minister Tony Blair, Russian President Vladimir Putin discounted the possibility of such an accident. Mr. Putin said that Ukrainian officials had informed Russia that their missiles did not have the range to have been able to reach the aircraft. He said a determination of the cause of the explosion should await a thorough investigation by experts.

Ukraine's defense ministry also denied its forces had accidentally shot down the plane.

Mr. Putin named Vladimir Rushailo, the man who heads the presidential Security Council, as chief of the investigation into the crash.

Russian security officials say they first learned that the plane had gone down from Armenia.

The captain of an Armenian plane in the area reported to air traffic control that he saw an aircraft explode, then fall into the sea.

Flight 1812 is a regular weekly charter that flies from Novosibirsk to Tel Aviv on Wednesday night then makes the return trip the following day. As the only service between Israel and Siberia it is very popular among Russian Jews who have immigrated to Israel.

Israeli authorities suspended all flight from Ben Gurion airport for several hours but have since resumed operations. The Israeli government has pledged full cooperation with Russian authorities as they investigate the causes of the crash. Rescue operations were launched almost immediately but the effort could be hampered by the fact that the sea at the crash site is some 1,000 meters deep.