DAMASCUS, Feb. 22 (Xinhua) -- Syrian military on Thursday urged civilians in Eastern Ghouta in east of Damascus to leave ahead of an imminent military offensive.

Syrian military helicopters dropped leaflets over the rebel-held areas, reported the War Media, the media wing of the Syrian army.

The civilians were requested to move to areas under the Syrian army control, as the leaflet included instructions on how to take safe exits illustrated on a small map.

The instructions also warned the civilians against cooperating with the anti-government rebels.

"Brother citizens in Eastern Ghouta, the area is surrounded by the Syrian army... Everyone is tired of this war that has brought nothing to the Syrians but death and destruction of the homes, hospitals, and schools," the leaflet said.

Because of the armed rebels, thousands of children, mothers, fathers, and brothers have lost their lives or ended up in shelters and camps, it continued.

"Our families in Eastern Ghouta, we hope you don't cooperate with the armed men to protect your lives and we call on you to leave the area as we guarantee your safety," it said.

The military also pledged to offer security and food to the people once they left Eastern Ghouta, promising them a safe return to their homes "after the elimination of terrorism."

This development came as massive military reinforcements have reached the outskirts of Eastern Ghouta as part of the preparations for a military campaign to defeat the rebels in that sprawling area, including the al-Qaida-linked ones.

Eastern Ghouta has seen intense bombardment in recent days, as a prelude to the anticipated military campaign.

The recent violence in eastern Damascus was triggered a couple of months ago when al-Qaida-linked groups launched an offensive against a key military base in the city of Harasta in the rebel-held Eastern Ghouta region, prompting a counter military offensive in that area.

The attacks at that time were coupled with rebels' shelling of the capital Damascus, against which Syrian government troops retaliated by launching airstrikes targeting the rebel positions in Eastern Ghouta.

But the situation has dramatically worsened in recent days, creating a humanitarian crisis that has attracted the international attention.

The rebels' mortar shells have rained down on Damascus so heavily that the life in the Damascus' eastern neighborhoods near Eastern Ghouta has been largely paralyzed with people cowering in their homes, not daring to leave for safety reasons.

The hospitals in Damascus, mainly those close to the east, have been jam-packed with wounded people and children. Moreover, residents in eastern Damascus have refrained from sending their kids to the schools, as three children were killed on Tuesday when a mortar shell struck their school in central Damascus.

Late last Sunday, the Syrian army amassed forces on the outskirts of Eastern Ghouta and started heavily shelling the rebel positions.

Eastern Ghouta, where around 350,000 civilians are still living, has for long been the major threat to the capital Damascus, with rebels keep launching attacks at the capital.

Four key rebel groups are positioned inside Eastern Ghouta, including the Islam Army, Failaq al-Rahman, Ahrar al-Sham and the Levant Liberation Committee (LLC), otherwise known as the al-Qaida-linked Nusra Front.

The Syrian Observatory for Human Rights said that 400 people have been killed and hundreds of others wounded by the bombardment of Eastern Ghouta since Sunday.

The Syrian Arab Red Crescent (SARC) said Thursday that two of its subbranches in Eastern Ghouta had been damaged, adding that several of its workers were wounded.

It urged the conflicting parties to separate its centers from the military targets.

The UN has urged for a one-month long cessation of hostilities to enable its teams on the ground to deliver relief aid to the affected civilians inside Eastern Ghouta.

On Thursday, the UN Security Council held an emergency session to discuss the situation in Eastern Ghouta.

Mark Lowcock, UN undersecretary-general for humanitarian affairs and emergency relief coordinator, on Thursday called on the Security Council to take "urgent and concrete action" as violence escalates in Syria.

The international community must take "urgent and concrete action," Lowcock told the council.

Meanwhile, Kuwait and Sweden put forward a draft resolution on reaching a month-long ceasefire and sending humanitarian relief to Eastern Ghouta.

But the Russian envoy to the UN Vassily Nebenzia said that Russia would not support the resolution put forward by Sweden and Kuwait in its present form, calling it unrealistic.

Later on, news was circulated that voting on the resolution is postponed till Friday amid information about Russian amendments to the draft.

For his part, Bashar al-Jaafari, the Syrian envoy to the UN, told the UN Security Council session that the draft resolution submitted by Kuwait and Sweden was not coordinated with the Syrian delegation.

The Syrian diplomat noted that groups in Eastern Ghouta designated as terror organizations by the UN Security Council have been targeting Damascus with hundreds of rockets and mortar shells on a daily basis, causing the death and injury of dozens of civilians.

The remarks by al-Jaafari and the Russian envoy indicate that there will be no tolerance with the rebels in Eastern Ghouta as the decision has apparently been made to eliminate the rebels.