Jewish girls take part in the first day of a pilgrimage at the Ghriba synagogue in Djerba May 9, 2012. REUTERS/Anis Mili

Security concerns and threats from some Salafi Islamists kept thousands of Jewish pilgrims away from the annual  Lag Ba’omer celebration on the Tunisian island of Djerba this week.

No more than 500 pilgrims attended the religious festival celebrated a month after Passover at one of Africa’s oldest synagogues on Wednesday and Thursday – an event that used to attract thousands of visitors.

Numbers have plummeted since the overthrow of authoritarian secular leader Zine al-Abidine Ben Ali in a popular uprising in January last year, leading to months of political uncertainty, and the rise to power in October of an Islamist-led government.

Israel issued a travel advisory urging its citizens ahead of the festival to “avoid” visits to Tunisia this year, citing information suggesting they might come under attack.