Explosion hits bus carrying Israeli tourists in Bulgaria airport; at least 4 killed Smoke rises over the Bourgas airport in Bulgaria, after an explosion on Wednesday. Three people were killed and more than 20 wounded in an apparent bomb attack on a bus packed with Israeli passengers at a Bulgarian airport, officials said, with media saying the toll would rise. ET: SOFIA, Bulgaria -- An explosion on a bus carrying Israeli tourists at an airport in Burgas killed at least four people and injured at least 30 others, Bulgarian authorities said. Bulgarian officials could not confirm the deadly blast was terror-related but Israeli Prime Minister Benjamin Netanyahu blamed Iran. "Iran is responsible for the terror attack in Bulgaria, we will have a strong response against Iranian terror," said Netanyahu in a statement, according to Haaretz, an Israeli newspaper. The bus was thought to have just departed Burgas Airport en route to a hotel when the explosion happened. "I do not know what it was, but it was a very powerful blast, and I think it was something placed on purpose in the bus, which carried 47 Israeli tourists," Burgas mayor Dimitar Nikolov told BTV television. The Bulgarian Press Office, which provided the casualty figures, said only one bus was involved in the explosion, but added the investigation is ongoing. An explosion damaged a bus carrying Israeli tourists at Bourgas Airport in Bulgaria on Wednesday. The incident took place in the Black Sea city of Burgas, some 250 miles east of the capital, Sofia. Bulgarian police have said that the deadly bus blast at Burgas airport was a terrorist attack, media reported. According to the Haaretz newspaper, a witness said the bus was ferrying people between terminals and that it went up in flames after the blast. The blast hit in a parking zone outside the airport where buses were waiting to take tourists to their hotels, the interior ministry said. The Jerusalem Post reported that the Israeli tourists had landed at the airport at 4:45 p.m. local time (9:45 a.m. Bulgarian police said they were investigating. The Israel Airports Authority announced disruptions in flights from Israel and Europe, according to Haaretz. NBC's Lawahez Jabari in Jerusalem and Reuters contributed to this report.