The fragile security situation in Tunisia, where radical Islamists are blamed for a wave of violence in recent months, makes it necessary to extend the state of emergency, Defence Minister Rachid Sabbagh said on Friday.

"The current security situation in the country requires an extension of the state of emergency," said Sabbagh, cited by the official TAP news agency.

The state of emergency, in effect since veteran strongman Zine El Abidine Ben Ali was ousted in a mass uprising and regularly renewed for up to three- month periods, is supposed to end on June 3.

At the end of April, President Moncef Marzouki back calls for it to be lifted.

But Sabbagh said the security measures taken under the state of emergency had to be rigorously applied, and that another extension was "highly likely."

Tunisia has suffered a wave of attacks blamed on hardline Salafists since the revolution, and the security security forces last month intensified operations against Al-Qaeda-linked jihadist groups hiding along the country's western border.

The government also banned the annual congress last Sunday of Ansar al-Sharia, considered the most radical of the extremist groups to have emerged since the revolution.

The move led to clashes between protesters and police in a suburb of the capital in which one person was killed and around 20 people wounded.