Officials in Bulgaria have said they believe the fatal blast on a tourist bus in the coastal resort of Burgos on Wednesday was the work of a suicide bomber.

Six people, including five Israelis and the Bulgarian driver, were killed in the explosion and many more injured and suffering from shrapnel wounds. The blast occurred not long after a flight from Tel Aviv carrying 154 passengers landed.

According to the Bulgarian interior ministry, the suspected bomber – who also died in the attack – had on him a Michigan driver's licence, which FBI agents said was a fake.

Iran's state TV has denied that Iranian agents of Hizbollah terrorists linked to the country were behind the attack. But the Israeli Prime Minister said: "All signs point to Iran.

"Just in the past few months, we have seen attempts by Iran to harm Israelis in Thailand, India, Georgia, Kenya, Cyprus and more.

"This is an Iranian terror attack that is spreading across the world. Israel will react forcefully to Iran's terror."

Emergency aid workers from Israel's Magen David Adom organisation, including paramedics and doctors, arrived in Burgas early this morning to help bring the 32 wounded people back to Israel and supervise the care of three who are seriously injured.

"All the wounded are in a stable condition and had received medical treatment, including surgery where necessary," said a spokesman.

A delegation from emergency organisation ZAKA also arrived in Burgas today to undertake the collection of the bodies and the remains and to return the bodies of the deceased to Israel.

Mati Goldstein, Zaka's international commander said: "This is a very difficult situation, we are dealing with corpses and gathering religious findings. We are working to bring all bodies to Israel as soon as possible."

The mayor of Sofia said that a bulked-up police presence was in operation to protect Bulgaria's Jewish community, which is estimated at between 5,000 and 7,000.