Tunis: Tunisia said Friday it has jailed or closely monitored 800 militants who have returned from foreign battlefields in the past decade.

“Some are in prison, some are under house arrest and others are under close surveillance”, government spokesperson Iyed Dahmani said of the fighters who have returned since 2007.

A little under 3,000 Tunisians have joined the ranks of terror groups fighting in neighbouring Libya, as well as in Syria and Iraq, Dahmani said.

The United Nations puts this figure at 5,000.

On Thursday, Prime Minister Youssef Shahed said all militants returning from fighting abroad would be immediately arrested and judged according to the country’s counter-terrorism law.

Shahed said authorities had “lists of all (Tunisian) terrorists” and “all the data on them”.

Last week, Interior Minister Hadi Majdoub told parliament that 800 militants had already returned from the front lines.

Concern about their return has increased since Tunisian Anis Amri, 24, was identified as the suspected attacker who mowed down 11 people at a Berlin Christmas market last week, and also killed the driver.

Tunisians rallied outside parliament at the weekend to protest against allowing militants back into the country.

The national union of internal security forces has called on the government to strip Tunisian Islamist militants of their nationality.

But President Beji Qaid Al Sebsi, citing the constitution, has said the authorities cannot prevent a Tunisian from returning home.

Since its 2011 uprising, Tunisia has faced repeated terror attacks, killing more than 100 soldiers and policemen, as well as about 20 civilians and 59 foreign tourists, according to official figures.