(CNN) -- An explosion on a bus in Bulgaria has killed several Israeli tourists and injured others, say authorities.
The explosion was "clearly a terrorist attack," Israeli Defense Minister Ehud Barak said Wednesday.
Vania Valkova, director of the Bulgarian interior ministry press office, said that at least six people were killed and about 30 injured in the explosion in a parking lot outside Burgas Airport, on the Black Sea coast.
Below is Israeli Prime Minister Benjamin Netanyahu's official statement regarding the incident:
"All signs point towards Iran. Over the last few months we have seen Iran's attempts to attack Israelis in Thailand, India, Georgia, Kenya, Cyprus and other countries. Exactly 18 years to the day after the horrendous attack on the Jewish Community Center in Argentina, deadly Iranian terrorism continues to strike at innocent people. This is a global Iranian terror onslaught and Israel will react firmly to it."
The Prime Minister sends his condolences to the families of the victims and wishes a speedy recovery to the wounded.