Djerba, Tunisia ? The death toll in a fiery truck crash at a Tunisian synagogue rose to at least 10 on Friday, as officials sought to deflect questions about how the explosion could have been an accident.

Six Germans, including an 11-year-old boy, and four Tunisians the truck driver, a tour guide and two synagogue workers were killed in Thursday’s crash at the historic Ghriba synagogue on the resort island of Djerba. Dozens of people were injured, mostly German tourists.

Tunisian officials quickly called the explosion a tragic accident, but the Israeli government said it was an attack.

German Chancellor Gerhard Schroeder said that if it was a terrorist attack, “those responsible must of course be called to account.” Germany sent two investigators to Tunisia.

The main damage to the ornate Ghriba synagogue occurred at its entrance, where a painted ceiling was charred and the stained-glass window panes were blown out.

Andrea Esper, a German tourist who was in the synagogue at the time, said that she had heard windows breaking and people screaming, “but I can’t tell you if it was an attack.”

Five people were reported killed immediately and five more died of their injuries.

The explosion followed a spate of attacks on Jewish targets in Europe stemming from the escalation in fighting between Israelis and Palestinians.

Perez Trabelsi, the synagogue’s president, said he thought the crash was an accident, as did the regional governor, Mohamed Ben Salem.

According to Ben Salem, police said the natural gas tanker was stopped by synagogue guards as it approached the grounds and was ordered to turn around. As it turned, it hit the outer wall and exploded.

Germany’s Bild newspaper gave another account. Citing unidentified German government sources, Bild said the tanker had been parked in front of the synagogue, and the driver allegedly triggered the explosion when guards approached him.