There are less than 2,000 Jews in Tunisia, mostly living in Zarzis and the nearby island of Djerba in the south of the country.
“The security forces aborted a plan to kidnap young Jews in Zarzis. Police arrested four young men and seized two weapons,” the official, Lofi Hidouri, told Reuters.
Perez Trabelsi, head of the Jewish community in Djerba, said a policeman was among the four arrested.
“There is a big worry in Djerba and Zarzis. The government should provide us with more protection,” Trablesi said.
An “intimidation campaign” was underway to force Jews to leave Tunisia, he said.
“This our country, we will not leave it”, he added.
Tunisia, whose authoritarian president, Zine El Abidine Ben Ali, was overthrown in a street revolt in January 2011, now has an elected Islamist-led government.
Friction has grown between Islamists and secularists, with hardline Salafi Muslims clashing with police in street protests.
A few weeks after Ben Ali fled Tunisia, a synagogue in the city of Ghabes was set alight.
No one was hurt and the incident appeared to be isolated, but it revived memories of an al Qaeda attack in 2002 that killed 21 tourists after an explosive-laden truck Blew up near a synagogue in Djerba.