The civil unrest which resulted in the ousting of Tunisia's long-time president displays an instability prevalent in the entire Middle East, Prime Minister Benjamin Netanyahu said on Sunday, adding that the situation highlighted the need for security assurances in a future Mideast peace deal.

Massive street protests over corruption and unemployment forced President Zine El Abidine Ben Ali to flee the country Friday night after 23 years of iron-fisted rule.

Saudi King Abdullah's palace confirmed early Saturday that the ousted president and his family had landed in Saudi Arabia, saying the kingdom welcomed him with a wish for "peace and security to return to the people of Tunisia."

Speaking during the cabinet's weekly meeting in Jerusalem, Netanyahu said that recent turmoil in Tunisia was an example of "how unstable Israel's region is."

"There are several centers of instability in our region and we hope that peace and security return to the region," Netanyahu said.

Netanyahu added that the Tunisian unrest also highlights an important issue regarding a possible Middle East peace treaty, saying that there is doubt whether or not such an agreement would be followed by all sides in the long run in view of the pervasive political instability in the region.

"We don't know if a peace agreement would be respected and so any peace deal would have to include on-the-ground security arrangements," the premier said.

Unrest engulfed Tunisia on Saturday after a popular rebellion forced the president to flee. Dozens of inmates were killed in a prison fire, looters emptied shops and torched the main train station and gunfire echoed through the capital.

Power changed hands for the second time in 24 hours in the North African country after the president fled the country Friday, with the head of the Constitutional Court declaring that Ben Ali had left office for good, not temporally, negating the prime minister's move to assume power.

Fouad Mebazaa, the former parliament speaker, was sworn in as chief of state on Saturday. He says he asked the premier to form a national unity government in the country's best interests.

Mebazaa said in his first televised address that all political parties including the opposition will be consulted without exception or exclusion.

Anger over corruption and the lack of jobs ignited a month of protests, but Ben Ali's departure - a key demand of demonstrators - has not calmed the unrest. While the protests were mostly peaceful, after Ben Ali's departure rioters burned the main train station in Tunis and looted shops.

A fire in a prison in the Mediterranean coastal resort of Monastir killed 42 people, coroner Tarek Mghirbi told The AP on Saturday. The cause of the fire was not immediately clear.

Sporadic gunfire was heard in the capital of Tunis on Saturday. Smoke billowed over a giant supermarket outside the capital as looters torched and emptied it. The army fired warning shots to scare them away, to little avail.