TUNIS, May 9 (Xinhua) -- A guardsman affiliated with the National Guard killed four people on Tuesday night at La Ghriba synagogue on the island of Djerba, south Tunisia, the Tunisian Interior Ministry said.

The guardsman killed a colleague and seized his ammunition before heading toward the synagogue, the ministry said in a statement. He opened fire at security units stationed near the synagogue, leaving two visitors and another security officer killed, before being killed during an exchange of fire.

At least five security officers and other four civilians were injured and rushed to hospital for treatment.

"The synagogue and its possessions were cordoned off and all those inside and outside were secured," said the ministry, adding that an investigation was underway to determine the motive behind the "treacherous and cowardly" attack.

Local media reported earlier that an exchange of fire near the Ghriba synagogue was heard, coinciding with the conclusion of the annual celebrations of hundreds of Jews from local communities and other countries.

The Ghriba synagogue, one of the oldest synagogues in Africa, has fallen victim to terror attacks. In 2002, a suicide bombing at the synagogue killed 21 people and a soldier shot dead five people, including four Jews in 1985.