Six people were killed and dozens injured by an explosion on a bus carrying Israeli tourists outside an airport in Bulgaria that the Israeli prime minister immediately blamed on Iran.
The mayor of Burgas, on Bulgaria's Black Sea coast, said the bus was carrying Israeli tourists, but police could not immediately confirm their nationality.
Police said several other buses at the site had been damaged.
Israeli Prime Minister Benjamin Netanyahu blamed Iran for the blast and said Israel would respond.
"All the signs lead to Iran. Only in the past few months we have seen Iranian attempts to attack Israelis in Thailand, India, Georgia, Kenya, Cyprus and other places," Mr Netanyahu said in a statement.
Israeli diplomats have been targeted in several countries in recent months by bombers who Israel said struck on behalf of Iran.
Mayor Nikolov said 171 people had arrived on a plane from Israel to spend their holiday at the Black Sea coast. One American and one Slovenian passenger were on board.
Bulgarian Foreign Minister Nikolai Mladenov said the explosion was caused by a bomb on the bus. Thirty-two people were taken to hospital with injuries.
Burgas airport was closed after the incident and flights were redirected to the airport of Varna.
Israeli rescue services were planning to send a plane to Burgas with medical staff to treat the injured and take bodies home, the Israeli ambulance service Magen David Adom said.
