A military court in Tunisia has sentenced toppled president Zine el Abidine Ben Ali to 20 years imprisonment in absentia on various charges including incitement to murder.

Ben Ali, who is exiled in Saudi Arabia, was found guilty of "inciting disorder, murder and looting," the court said on Wednesday in its verdict over the deaths of four youths, shot dead in the town of Ouardanine in mid-January 2011.

Four protesters were shot dead in the eastern coastal town as they tried to prevent the flight of Ben Ali's nephew Kais, a day after Ben Ali flew out of the country on January 14.

The victims' relatives have accused the security apparatus of ordering police to open fire on the crowd.

The court also imposed prison sentences of five to 10 years, some in absentia, on several members of the security forces over the same incident.

Death penalty sought

Ben Ali faces countless trials and has already been sentenced to more than 66 years in prison on a range of other charges including drug trafficking and embezzlement.

He and his wife are the subject of an international arrest warrant, but Saudi authorities have not responded to Tunisian extradition requests.

A military prosecutor is also seeking the death penalty against the former president over a similar incident which saw at least 22 people killed in pro-democracy protests in the towns of Thala and Kasserine.

The weeks of protests that started in December 2010 toppled one of the most tightly controlled regimes in the Arab world and led to democratic elections in October that saw a moderate Muslim party rise to power.

It also set off a wave of protests which became known as the Arab Spring and is still sweeping the region.