Seven people were killed in an attack on an Israeli tour bus at the Sarafovo International Airport in the Bulgarian vacation city of Burgas on Wednesday afternoon. More than 30 were injured, three of them critically.

A bomb was placed in the bus, detonating to murderous effect. The impact was so strong as to damage two other buses nearby, also with Israelis on board. Some initial reports said the attack was a suicide bombing, but the preliminary investigation pointed to the bomb having been placed in a suitcase in the vehicle’s luggage hold or affixed to the side of the bus.

Israeli officials, from the prime minister on down, said Iran was to blame for the attack. Foreign Minister Avigdor Liberman specified that Iran’s Islamic Revolutionary Guards Corps was responsible.

Israeli medical teams were flying out to Burgas late Wednesday.

Nearly all the casualties were understood to be Israelis, but one of the dead was said to be a Bulgarian. Ten Israelis were in surgery in Bulgaria late Thursday.

Israel canceled all commercial planes to Bulgaria and upgraded security for all flights in and out of Ben-Gurion Airport.

Smoke rising from the Sarafovo Airport in Burgas, Bulgaria, after a terror attack on an Israeli tour bus, July 18, 2012. (photo credit: JTA/Burgasinfo)

Smoke rising from the Sarafovo Airport in Burgas, Bulgaria, after a terror attack on an Israeli tour bus, July 18, 2012. (photo credit: JTA/Burgasinfo)

A Bulgarian charter plane with 150 passengers from Tel Aviv to Burgas landed at 4:50 p.m. local time, and its passengers boarded buses to take them from the terminal to their hotels. The explosion occurred a short time later — apparently in the second of the four buses in the convoy.

Almost all of the passengers on the Bulgarian Air Via charter flight were Israelis, along with one American, one Italian and a Slovakian.

The White House condemned the attack “on innocent people, especially children, in the strongest possible terms.”

White House press secretary Jay Carney said President Barack Obama’s “thoughts and prayers are with the families of those killed and injured.” Carney added that the US stood with the Israeli people and the people of Bulgaria.

The EU also issued a statement condemning the attack.

Prime Minister Benjamin Netanyahu said, “All the signs point to Iran. Just in the last few months, we saw Iran attempting to hurt Israelis in Thailand, India, Georgia, Kenya, Cyprus and other countries. Exactly 18 years after the infernal terror attack in the Jewish community center in Argentina [in Buenos Aires, in which 85 people were killed], the murderous terror of the Iranians continues to hurt innocent people. This is terrorist Iranian aggression revealing itself all over the world. Israel will respond forcefully to the Iranian terror.”

Defense Minister Ehud Barak, too, placed the blame squarely on Iran and Hezbollah. “We will know how to get to those who are responsible,” he said.

Deputy Foreign Minister Danny Ayalon told Channel 2 News that Israel would not only “submit a complaint about Iran to the UN Security Council” but push for sanctions against the country– “not only for its nuclear program but because of its terror activities.” He said Israel would seek to ground Iran’s planes and push for its citizens to be prohibited from touring countries around the world.

Some reports said three pregnant women were on the bus. Initial rumors that members of an Israeli youth basketball team was present at the scene of the tragedy were dispelled.

Aron Katz, an Israeli eyewitness, said that a few moments after they got on the bus, “we heard a really loud boom, and felt the bus shake, and we ran off the bus.”

Katz noted that he saw several couples on the bus, some with young children. “I tried to get back on the bus after the explosion to get my daughter’s wheelchair, but they wouldn’t let me. I saw a woman lying unconscious, and tried to wake her,” Katz said, adding that the scene was very chaotic.

The Burgas airport was subsequently closed and all flights were redirected to Varna.

Foreign Minister Liberman spoke to his Bulgarian counterpart, Nickolay Mladenov, after the explosion. Mladenov and Israeli ambassador to Bulgaria Shaul Camisa Raz made their way immediately to the site.

Already present were Bulgaria’s President Rosen Plevneliev, Prime Minister Boyko Borisov, Interior Minister Tsvetan Tsvetanov and Health Minister Desislava Atanasova.

Arthur Kol, in charge of communications at the Foreign Ministry, said Bulgaria had not received any prior intelligence from Israel about a possible attack.

There had been a meeting between the Mossad and Bulgarian intelligence a few weeks ago, but no specific warning of a terror attack.

Idan Ruben, a local tour guide in Burgas, told Channel 10 that the bomb went off “as soon as people entered the bus.” He said the bus was filled with 44 people, all Israelis, and most of them youths.

Israeli emergency service ZAKA and Magen David Adom (MDA) were sending planes to Burgas, and MDA said it would try to fly the wounded home to Israel for treatment.

Iran and its proxy, Lebanese-based terror group Hezbollah, were the immediate prime suspects in the attack. Israel has thwarted numerous Hezbollah terror attacks in recent years. Hezbollah’s Al-Manar TV station was broadcasting details of the bombing, with excited commentary, on Wednesday evening, Israel’s Channel 2 reported.

A tour bus that was attacked in the Bulgarian city of Burgas burns on Wednesday (photo credit: Channel 10 screen capture)

A tour bus that was attacked in the Bulgarian city of Burgas burns on Wednesday (photo credit: Channel 10 screen capture)

In January, the Foreign Ministry warned of a possible terror plot against Israelis in Bulgaria, urging Israelis to take extra precautions when traveling there. It also asked the Bulgarian government to implement extra security measures to ensure that Israeli tourists remain safe.

Last week, a suspected Hezbollah attack on Israeli tourists in Cyprus was foiled by Cypriot authorities. It was unclear whether Wednesday’s attack was related, but the Lebanese terrorist organization swore revenge against Israel, after the assassination of its terror chief, Imad Mughniyeh, in February 2008.

Hezbollah leader Hassan Nasrallah made no mention of the Bulgaria terror attack in a speech he gave in Beirut late Wednesday.

Nitzan Noriel, former head of the government’s Counter-Terrorism Bureau, told Channel 2 News that Hezbollah and Iran targets countries like Bulgaria because they have their own Muslim populations and have proximity to Lebanon and Iran, with direct flights from Iran, he added. Channel 10 also explained that Iranian-backed agents target Israelis in countries that they can easily enter, referring to Thailand and India.

Burgas is the second-largest city on the Bulgarian Black Sea coast. It has become a very popular destination for Israeli tourists over the past few years, in the wake of Turkey’s dramatic break with Israel.