Syrian forces rained barrels bombs on Aleppo Thursday, as they pressed a campaign against rebels in the northern city where dozens have been killed this week, a monitor said.

The Britain-based Syrian Observatory for Human Rights also said jihadist fighters executed 15 civilians in the northeastern province of Hasakeh.

The commander of the rebel Free Syrian Army urged Syrians to boycott Tuesday's presidential election, calling it a "farce" run by a "criminal" regime.

The vote, which will be held only in territory controlled by the regime, is expected to see President Bashar Assad trounce two little-known rivals and gain a third seven-year mandate.

March 14 General Secretariat Coordinator Fares Soaid on Thursday called for taking “necessary measures” towards Syrians “moving freely” between Lebanon and Syria, stressing that they are not part of the refugees who have fled “the killing machine called Bashar Assad.”

“The scene of the Syrian presidential elections that were held in Lebanon raises a question mark regarding the definition of a Syrian refugee. Do all Syrians residing in Lebanon really need to be in Lebanon?” Soaid said after meeting Lebanese Forces leader Samir Geagea in Maarab.

The European Union said Thursday it was renewing economic sanctions against Syria, including an oil embargo and asset freezes against allies of President Bashar Assad, for another year.

The measures, which will extend to June 1, 2015, affect 179 people "associated with the violent repression in Syria", and 53 entities, including the Central Bank of Syria, the EU said in its Official Journal.

Three years of civil war in Syria have had a disastrous effect on the economy, plunging half the population into poverty, a Syrian research center said in a report released Thursday.

"Squandering Humanity" was produced by the Damascus-based Syrian Center for Policy Research in conjunction with the U.N. Development Program and the U.N. Palestinian refugee agency.

The United States, Russia and the Middle East must "find the courage for united action" on Syria, the Vatican said Thursday ahead of a meeting of aid groups on the crisis.

The international community "must shake off its lethargy," Guinean Cardinal Robert Sarah, head of the Vatican Cor Unum department which coordinates Roman Catholic charities, said in an interview with La Stampa's Vatican Insider.

Hundreds of Syrians living in Lebanon have lined up outside their embassy near Beirut to vote ahead of their country's June 3 presidential election as expat balloting was extended for another day.

Expat voting in Lebanon was extended through Thursday after Syrian voters clashed with Lebanese troops outside the embassy the day before.

UNHCR's representative in Lebanon Ninette Kelley warned on Thursday of the presidential vacuum's repercussions on attracting foreign financial support and investments to enable the country deal with the refugee crisis.

"Presidential vacuum decreases international trust in Lebanon,” Kelley said in an interview with An Nahar daily published on Thursday.

Syria's divided rebels and their foreign backers have been watching in disbelief as the regime gears up for an election to give Bashar Assad another presidential mandate despite their uprising.

The vote, which the Damascus regime can hold only in territory it controls and embassies abroad, signals confidence by Assad and his allies that they will win the war.

For Abu Nur, a Syrian war refugee in northern Lebanon, next week's certain re-election of Syrian President Bashar Assad buries any hope he had of returning home soon.

It will now take a "miracle from God, the all-powerful" to end the more than three-year-old conflict in Syria, the forty-something said from his grubby lodgings in the port city of Tripoli.