BEIRUT (AP) ― The U.N.-Arab League envoy for Syria warned Tuesday that the country could become another Somalia ― where al-Qaida-linked militants and warlords battled for decades after the ouster of a dictator ― if the civil war is not ended soon.

Battles between regime forces and Syrian rebels left more than 140 people dead across Syria on Tuesday, while the brother of Syria’s parliament speaker was gunned down in Damascus ― the latest victim of a wave of assassinations targeting high-ranking supporters of President Bashar Assad’s regime.

Among the dead were at least 13 people who died in a series of explosions in the capital Damascus, targeting impoverished districts of the capital. Dozens others were wounded, activists said.

The violence aroused new concern about the faltering diplomatic efforts to try to end the conflict, with the U.N. political chief warning that the Syria crisis risks “exploding outward” into Lebanon, Turkey and Israel.

Britain’s prime minister offered the latest long shot ― that Assad could be allowed safe passage out of the country if that would guarantee an end to the fighting.

But there has been no sign the embattled Syrian leader is willing to step down as part of a peaceful transition to save the country. Assad has vowed to militarily crush the nearly 20-month old rebellion against his rule, and aides say a new president will only be chosen in elections scheduled for 2014.

U.N.-Arab League envoy Lakhdar Brahimi, who, like his predecessor Kofi Annan has been unable to put an end to the conflict, warned the civil war could spiral into new levels of chaos.

“The situation in Syria is very dangerous,” Brahimi said in remarks published Tuesday in the pan-Arab daily Al Hayat. “I believe that if the crisis is not solved ... there will be the danger of Somalization. It will mean the fall of the state, rise of warlords and militias.”

Somalia has been mired in conflict for more than two decades after warlords overthrew the east African nation’s longtime dictator in 1991 and then turned on each other. The government, backed by African Union troops, is currently battling Islamist extremist rebels linked to al-Qaida.

Syria, by comparison, has always had a strong central government, and despite losing large swathes of territory, the regime still maintains a grip on many parts of the country, including Damascus, the seat of Assad’s power, where basic government services still function.

But if the regime collapses, the country could fast shatter along multiple fault lines, leading to protracted bloodshed.

The predominantly Sunni nation is a patchwork of religious and ethnic groups. The regime is led by Assad’s Alawite minority, an offshoot of Shiite Islam, but there are also considerable Kurdish and Christian populations.

The conflict’s already increasing sectarian overtones suggest any power vacuum could usher in renewed violence. Predominantly Kurdish areas in the north and Alawite majority areas in the central coastal mountains could spin away, and mixed areas ― already hard hit by the conflict ― could plunge further into conflict.

Dozens of opposition groups and rebel brigades have taken up the fight against Assad. But they share little common vision for the future and are divided by acute ideological differences, particularly among secularists and Islamists, and could easily turn on one another after Assad’s fall.

There are also growing concerns over the injection of al-Qaida’s influence into the country’s civil war. Jabhat al-Nusra, a shadowy jihadi group with an al-Qaida-style ideology, has carried out numerous suicide bombings targeting regime and military facilities.