VIENNA, Austria (AP) _ A Balkan Bulgarian airlines jet crashed shortly after taking off from Sofia on Tuesday, killing 23 people and injuring 14, the official Bulgarian news agency said.

Bulgarian airport officials reached by telephone from Vienna confirmed the crash, but refused to give details.

The Yak-40, a Soviet-built plane with three engines, crashed at 5:29 p.m. (10:29 a.m. EDT) at the start of a 280-mile scheduled flight from the Bulgarian capital to Varna on the Black Sea coast.

The plane carried 33 passengers and four crew members, BTA said. It did not say whether any foreigners were aboard.

It said 14 people were hospitalized ''for emergency treatment. The rest were killed in the crash,'' BTA said.

The agency said a commission had been appointed to investigate the crash.

The accident was believed to be the worst Bulgarian air disaster since the crash of Bulgarian airliner that was preparing to land in Sofia in 1984. All 50 people on board were killed in that accident, involving a Tu-134 jet.

In 1978, a Balkan Bulgarian plane en route from Sofia to Warsaw crashed and killed 73 people.