TUNIS, Tunisia >> A Tunisian naval guard shot and killed a colleague and two civilians Tuesday as he tried to reach a synagogue on the Mediterranean island of Djerba during an annual Jewish pilgrimage, the Tunisian Interior Ministry said. The attacker was slain by security guards, and 10 people were injured.

The motive for the attack was under investigation. It came as Tunisia, once a prized tourist destination and birthplace of the Arab Spring pro-democracy uprisings, has fallen into political and economic crisis.

Djerba, a picturesque island off the southern coast of Tunisia, is home to the North African country’s main Jewish community.

The civilians killed were French and Tunisian, the Tunisian Foreign Ministry said. It was not immediately clear if they were pilgrims attending ceremonies at the 2,500-year-old Ghriba temple, one of Africa’s oldest synagogues.

Those injured include six security agents and four civilians, the Interior Ministry said. It did not specify how they were injured or whether they were all shot by the attacker, who was not publicly identified.

The assailant, a guard affiliated with the National Guard naval center in the port town of Aghir on Djerba, first killed a colleague with his service weapon and then seized ammunition and headed toward the Ghriba synagogue, the ministry said.

When he reached the site, he opened fire on security units stationed at the temple, who fired back, killing him before he reached the entrance, the ministry said. The synagogue was locked down and those inside and outside were kept secure while authorities investigate the motives for the attack, the ministry said.

Ghayda Thabet, a member of the Tunisian Association for the Support of Minorities, was at the Ghriba synagogue and appealed for help on Facebook. “They are shooting with live ammunition. Help us,” she pleaded in a post.

Videos circulating online showed panic-stricken visitors running while gunshots rang out.

It occurred during an annual pilgrimage that attracts thousands of visitors from around the world to Djerba.

In 2002, a truck bombing killed some 20 people at the entrance to the same temple during the annual Jewish pilgrimage. Al-Qaida claimed responsibility for that attack, whose victims included German and French tourists as well as Tunisians.

In 2015, an attack in Tunisia at the Mediterranean resort of Sousse killed 38, mostly British tourists. The Islamic State group claimed that attack, along with attacks that year on the famed Bardo Museum in the capital Tunis and on a bus carrying presidential guards.