(Reuters) - In the Jewish quarters on the Tunisian island of Djerba, only menoras or Hebrew letters painted in blue against the whitewashed walls distinguish a Jewish home from the Muslim family living next door.

Mainly Muslim Tunisia is home to one of North Africa´s largest Jewish communities. Though they now number less than 1,800 people, Jews have lived in Tunisia since Roman times.

The El Ghriba synagogue in Djerba, home to most of Tunisia´s Jews, is built on the site of a Jewish temple that is believed to date back almost 1,900 years and attracts pilgrims each year.

But more than a year after Tunisia´s revolution ousted Zine al- Abidine Ben Ali and sparked uprisings around the region, uncertainty over the democratic transition and threats by some Salafi Islamists have begun to raise fears that decades of peaceful co-existence could begin to erode.

Sitting in his jewelry shop in Djerba´s covered souk, David Bitan said life for Tunisia´s Jews was changing, much as it has for all Tunisians since the revolt. Business had yet to recover and the instability that dogs Tunisia affected them too.

"We are not afraid of Salafis who talk too much. We´re afraid of those who say nothing, then do something," said Bitan.

"Things have changed since the revolution. Before, people were afraid of the police. Now, we are under pressure. The police is weak, so racism is increasing. People are not afraid."

The pilgrimage to Djerba, which attracted a peak number of 10,000 pilgrims in 2000, was cancelled last year because visitors were reluctant to wade into the charged political environment of the Arab Spring. Less than 100 made the journey.

Ahead of this year´s event around May 9 - the anniversary of the death of a second century Jewish scholar - Tunisia´s new Islamist-led government has been at pains to assure Jews that they are welcome.

But news of occasional unrest, such as a day of clashes between police and protesters on April 9, still spooks visitors thinking of making the pilgrimage, mainly from Germany and France.

Tunisia´s Jewish community once numbered 100,000 people. But fear, poverty and discrimination prompted several waves of emigration after the creation of Israel in 1948. Many left after the 1967 Arab-Israeli war. Most went to France or Israel.

Leaning against the wall in the internal courtyard of his traditional home, Perez Trabelsi, president of El Ghriba synagogue and spokesman for the Jewish community in Djerba´s Hara Sghira, or small quarter in Arabic, hopes the pilgrims will return.

"It could be 2,000, 3,000, 4,000. It is too early to say... We had 400 people planning to come, but then April 9 happened and they changed their minds. It scares foreigners, but we are not scared," said Trabelsi, adjusting his white skull cap.

"Whatever number of pilgrims come, the important thing is we hold the pilgrimage."

SALAFI THREATS

In February 2011, only 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 truck bombing that killed 21 people, most of them German visitors, at El Ghriba in 2002.

Officials of the moderate Islamist Ennahda party met with Jewish leaders after they won Tunisia´s first post-revolution elections in October to assure them their lives would not change.

But more conservative Salafi Islamists have been less tolerant. At a rally calling for an Islamic state, which took place in the capital in March, one Salafi speaker was heard inciting violence against Jews. The president, the speaker of parliament and the head of Ennahda condemned the comments.

But they followed a similar incident in January, when some of the Islamists who welcomed Ismail Haniyeh, a head of the Palestinian Islamist movement Hamas, at the airport chanted "kill the Jews -- it´s a religious duty."

Again, the government and politicians from across Tunisia´s political spectrum condemned the chants.

Chatting with friends outside a shop selling brik or fried pasties, Haim, who gave only his first name, said Tunisian Jews had the same concerns as all Tunisians.

"We are Tunisians ... Ask me what my priority is as a Tunisian and I will tell you that it is creating jobs for the desperate young people in Djerba, Medenine, Gafsa and Sidi Bouzid so another revolution is not sparked," he said.

"The Jews of Djerba are an inseparable part of this country and we are not asking for any special protection... There is no cause to fear extremist Islamists... Just as it is their country, it is our country too. Tunisia is for all."

A PROBLEM FOR EVERYONE

Concrete balustrades block the road into El Ghriba, whitewashed and decorated on the inside with blue ceramic tiles. Visitors must go through security checks before entry.

Inside, a few men in skull caps sit on benches praying. Outside, workers paint the walls to get ready for the pilgrimage.

In April, President Moncef al-Marzouki attended a ceremony marking a decade since the al Qaeda bombing. The number of pilgrims, which plummeted after the attack, had recovered to some 5,000 annually before last year´s uprising, according to Trabelsi.

The pilgrimage is a boon for both Muslim- and Jewish-owned businesses that rely on tourism on this holiday island.

"It was good that the president came. The tourists will consider it a good gesture," said Youssef Gamoun, who has run a shop selling silver jewelry in Djerba for 40 years. "Lots of people come to visit El Ghriba and I think they will come this year.

"We are neighbors with the Muslims. The lack of security is a problem for everyone, not just for us." (Editing by Sonya Hepinstall) (© Thomson Reuters 2012. 05/04/12)