The United Nations has expressed its "grave concern" over the detention in Tunisia of a UN expert tasked with investigating violations of a Libya arms embargo.

"The arrest and detention by the Tunisian authorities of Moncef Kartas... while he was performing his official duties is a matter of very grave concern," the spokesman for the UN secretary-general said in a statement Friday. 

After years of anxiously waiting in cramped prison cells, appointments with the noose can come fast to the many on Egypt's death row. 

The United Nations on Friday urgently appealed for the release and evacuation of more than 1,500 detained refugees and migrants caught in the crossfire of escalating fighting sparked by a self-styled Libyan army commander's military campaign to take the capital.

The U.N. refugee agency said the refugees and migrants are believed to be trapped in detention centers where hostilities are ranging.

It's Arab Spring, season II, and he's one of the few holdovers. The last man standing among a crop of Arab autocrats, after a new wave of protests forced the removal of the Algerian and Sudanese leaders from the posts they held for decades.

Syria's President Bashar Assad has survived an uprising, a years-long ruinous war and an Islamic "caliphate" established over parts of his broken country. As the Syrian conflict enters its ninth year, the 53-year-old leader appears more secure and confident than at any time since the revolt against his rule began in 2011.

An Israeli air strike in central Syria wounded three combatants early Saturday, the official SANA news agency reported.

More than 8,000 people have fled fighting around Libya's capital, half of whom have been displaced over the last two days, the United Nations said Friday. 

Strongmen in the Middle East and North Africa will be eyeing warily popular protests, fed by frustration with living standards and an elite perceived as corrupt, that helped push veteran Algerian president Abdelaziz Bouteflika and now Sudan’s Omar al-Bashir from power.

While recent events in Algeria and Sudan have been unique to those countries, analysts say the rapid downfall Bouteflika and Bashir are a warning to authoritarian leaders in the region that they will ignore popular anger, especially over economic grievances, at their peril.

Algerian police tried but failed to disperse protesters gathered for the first Friday protests since the announcement of presidential elections to succeed ousted leader Abdelaziz Bouteflika.

The United States initially cheered on the Arab Spring but as fresh popular uprisings sweep through Sudan and Algeria, President Donald Trump has taken a more passive role, convinced that strongmen can be his best partners.

Italian Prime Minister Giuseppe Conte warned Thursday that the deteriorating situation in Libya could create a humanitarian crisis and increase the number of migrants crossing the Mediterranean.