A Black Sea coast town in Bulgaria became the scene of carnage when a bus carrying Israeli tourists exploded, killing at least five people and injuring at least 33. Nine people reportedly were missing.

The explosion Wednesday at Sarafovo International Airport in Burgas hit one of three tour buses carrying Israelis, Israel’s Channel 1 reported. Some news reports said a suicide bomber boarded the bus as it was taking the Israeli tourists to the terminal. Others quoted Burgas Mayor Dimitar Nikolov as saying that explosives were in the luggage area of the bus.

A video on Ynet showed black smoke billowing upward. Sirens at the scene could be heard.

The attack, which Israel’s government is blaming on Iran, comes on the 18th anniversary of the terrorist attack on the AMIA Jewish center in Buenos Aires that left 85 people dead. Israel, Argentina and many other governments blame Iranian agents for that incident; Tehran denies the allegations.

“All signs point to Iran,” Israeli Prime Minister Benjamin Netanyahu said. “In just the past few months we’ve seen Iran try to target Israelis in Thailand, India, Georgia, Cyprus and more. The murderous Iranian terror continues to target innocent people. This is a global Iranian terror onslaught and Israel will react forcefully to it.”

Israeli Defense Minister Ehud Barak added, “This is clearly a terrorist attack initiated probably by Hezbollah, Hamas, Islamic Jihad or another group under the terror auspices of either Iran or other radical Islamic groups. We are in a continual fight against them. We are determined to identify who sent them, who perpetrated [the attack], and to settle the account.”

The Lebanese-based Hezbollah, which is armed by Iran, denied responsibility for the attack, according to the website Novinite.com.

Bulgarian Prime Minister Boyko Borisov said his government “strongly condemns this aggression and terrorism.”

“Such a horrible act committed on the territory of a sovereign country, a member of the EU, is a provocation at the efforts of the democratic society towards world peace,”  Borisov said, according to the FOCUS News Agency. “I guarantee that we will investigate this incident so as to punish the perpetrators with the entire severeness of the law. I am convinced that the Bulgarian and the Israeli nations will get stronger and more united after this tragedy.”

The mayor of the Bulgarian capital of Sofia, home to nearly 5,000 Jews, ordered stepped-up police patrols of areas linked to the Jewish community, according to reports.

Lt.-Gen. Benny Gantz, the chief of staff of the Israel Defense Forces Chief, ordered the Home Front Command, the Israel Air Force and the Medical Corps to send a team to Bulgaria Wednesday night to provide medical care and to assist those injured as they return to Israel. The team is led by a senior IDF officer and includes doctors specializing in trauma, orthopedics, intensive care, surgery, burns and pediatrics.

Likewise, the Israel-based ZAKA Rescue and Recovery Organization told JTA that it hired a private jet to fly to Burgas. The plane, which is scheduled to land in Bulgaria at about 11 p.m. local time, is carrying seven volunteers, a doctor and a paramedic, as well as medical equipment to help identify the Israelis who were killed.

President Obama condemned the “barbaric terrorist attack,” according to The Associated Press. “As Israel has tragically once more been a target of terrorism, the United States reaffirms our unshakeable commitment to Israel’s security, and our deep friendship and solidarity with the Israeli people.”

Immediately after the explosion, Ben Gurion International Airport was closed, delaying 11 flights. However, the airport reopened between 2 a.m. and 5 a.m. to allow the flights to proceed.

Novinite.com reported that Bulgarian authorities foiled a bomb attack in January on a charter bus for Israeli tourists heading from the Turkish border to a Bulgarian ski resort. A bomb was found on the bus.