Syria's military announced it is forming a new commando force, calling on volunteers interested in "achieving the final victory against terrorism" to apply.
The announcement on Tuesday, which named the new force the Fifth Corps, didn't specify where it would be deployed.
After nearly six years of combat, the Syrian conscription-based armed forces has become overstretched and has increasingly relied on its regional allies that have boosted its numbers and capabilities.
Iran announced on Tuesday its 1,000th troop fatality in Syria since the war started in 2011.
Syria's army said it formed a new corps of volunteers to fight alongside its soldiers and allies against opponents of President Bashar al-Assad.
An army statement said the move came "in response to the rapid development of events, to support the successes of armed forces, and to meet people's wishes to put an end to terrorist acts in the Syrian Arab Republic".
The Fifth Attack Troops Corps of Volunteers will be made up of recruits over age 18 from across the country "not already eligible for military service or deserters", it said. It was not immediately clear how many people would be involved.
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Syria already conscripts its men at age 18 into the army. Before the war, service would last for two years but now many conscripts say they have served for several years, with no sign of being discharged.
Military analysts say the Syrian army's pre-war numbers were about 300,000 personnel, but its current size after almost six years of conflict is not known.
Young men are known to desert the army, leave the country, or pay bribes to avoid being drafted.
Syria's forces are bolstered by Iranian troops, Iran-backed militias, and fighters from Lebanon's Shia-Muslim Hezbollah group, as well as Russian air power.
They are fighting against anti-Assad rebels and ISIL.
|At least 141 civilians have been killed in a week of renewed bombardment on the rebel-held eastern half of Aleppo [AFP]
Also on Tuesday, the Syrian military urged rebels to pull out of east Aleppo and allow civilians to also leave, as it pressed an offensive to recapture the city's opposition-held sector.
The army, which has besieged the east for months, also demanded that rebels distribute food to civilians, while calling on residents to cooperate with its advancing troops.
The military air-dropped leaflets with a picture of a green bus like those used in the past to transport civilians and rebels from areas retaken by the government.
"To those involved in carrying weapons, we stretch out our hand to you. Reserve your place before it is too late," the leaflets read.
The picture showed the bus on a road marked "the path of salvation".
WATCH: The Disappeared of Syria
At least 141 civilians, including 18 children, have been killed in a week of renewed bombardment on the rebel-held eastern half of Aleppo, which has devastated its hospitals, the Syrian Observatory for Human Rights said on Tuesday.
The Britain-based war monitor said it had documented hundreds of injuries as a result of Russian and Syrian air strikes and shelling by government forces.
The assault began last Tuesday after a weeks-long pause in air strikes and shelling inside east Aleppo, although battles and air strikes did continue along the city's frontlines and in the surrounding countryside.
The Syrian Observatory said there were another 87 deaths of rebel fighters and people of unknown identity in the eastern sector.
It also documented 16 civilian deaths, including 10 children, and dozens of injuries as a result of rebel shelling of government-held west Aleppo.
Source: News Agencies