The war in Syria leaves 16,000 displaced people from eastern Aleppo, according to the UN

Up to 16,000 people have fled violence in the eastern region of Aleppo, one of the areas devastated by the war in Syria, with food stocks "practically finished" and every hospital bombed, he said Tuesday the head The United Nations.

On Monday night, the Syrian regime continued to strike east of Aleppo with aerial bombardments, while troops tore the territory in an operation to retake the enclave after more than four years of rebel control.

"I am extremely concerned about the fate of civilians as a result of the deeply alarming and chilling situation in the city of Aleppo," Stephen O'Brien, the UN's chief humanitarian officer, said in a statement.

"Initial reports indicate that up to 16,000 people have been displaced, many under precarious and uncertain situations.Thousands more are likely to have no choice but to flee if fighting continues to expand in the coming days, "the United Nations official added.

Government forces and paramilitary groups loyal to Syrian President Bashar al-Assad began a new offensive in eastern Aleppo on November 15, as the regime's warplanes continued to fight in the area to expel rebels and civilians .

They have made a rapid recovery of the territory since they entered the east of Aleppo this Saturday, taking a great portion of the northeast. Russian media quoted his defense minister as saying on Monday that 40 percent of the territory was in the hands of the regime, but sources consulted by CNN say that only 20 percent is recovered.

An activist at the Aleppo Media Center says at least 25 people have died and many others were injured during the night when the regime threw parachute bombs in the Bab al-Nayreb neighborhood.

"There are no means of transport or vehicles on the streets, so civilians are fleeing between 8 and 9 kilometers on foot, carrying what they can with them and their children, and leaving through the western part of Aleppo," An activist told CNN.

On 13 November, the UN distributed the last food rations and the humanitarian advisor of that organization, Jan Egeland last week warned that people in the area were about to starve.

Restore help

Eastern Aleppo has become the epicenter of Syria's civil war, much of that area decimated by regime attacks backed by Russian air power.

Assad has promised to take over the entire Aleppo, which has been divided for years between two: the regime-controlled western area, and the rebel-controlled eastern region.

The government has besieged the east several times, cutting off the outside world for both rebels and civilians, leaving communities on the verge of starvation without enough food, drinking water, fuel and medical supplements.

"I called on all parties to the conflict to restore basic humanitarian aid in Syria," O'Brian said. "I called for them to lift the sieges, making sure not to attack civilians, or civilian infrastructure, and to allow humanitarian organizations secure and unimpeded access to help save the displaced or be besieged."

It is believed that more than 200,000 people still remain in eastern Aleppo, many of them trapped.

Before the evacuations of the last days, UNICEF said that about 100,000 children were there.

Many are too scared to use the government's "human corridors" fearing reprisals once they escape. Others say the rebels forced them to stay.

The beginning of the end?

Retaking all of Aleppo could mark a point of return in the civil war of Syria, because that city is the last strength of the country's rebel forces. Regaining control would put the regime back in charge of the four main cities.

Some observers suggest that it would be from the beginning of the end of the uprising that began in 2011.

A solution to the war has eluded the international community for several years. Russia and the United States have become involved, usually standing in opposite places of the conflict.

Russia has repeatedly used its veto power in the United Nations Security Council to overturn proposed resolutions for the conflict.

French Foreign Minister Jean-Marc Ayrault called on the Security Council to meet and review the situation immediately.

"More than ever there is an urgent need for a cessation of hostilities and unhindered access to humanitarian assistance," Ayrault said in a statement, adding that the leader of the Aleppo district councils Brita Hagi Hasan , This Wednesday in Paris.

O'Brien also called for a political solution, saying that "the people of Syria have suffered too much and for a long time."

"More than anything, I hope that a road will soon be opened towards a political solution so that we can give a look of hope to the many millions of Syrian families that are hungry, sick and afraid for their lives tonight," he said.

A seven-year-old Syrian girl says goodbye to Twitter in the midst of bombings

A Syrian girl of seven years, which has attracted international attention tweeting about everyday life in the area controlled by the rebels in the east of Aleppo area, shared a message Sunday night saying his house had been bombed.

"Tonight we do not have a house, it was bombed and I only have debris. I saw dead and I almost died," tweeted Bana Alabed. On Monday, her mother posted an update saying the family was running away.

Syrian regime forces launched a ground assault on Saturday, snatching control of a number of neighborhoods from northeastern Aleppo to the rebels. It is the biggest victory for the Syrian regime since the uprising began more than five years ago.

Fatemah, Bana's mother told CNN that her home was directly impacted Sunday night, forcing them out onto the street to wait for the planes to leave and the bombing cease.

Fatemah, 26, set up a Twitter account for her daughter in late September to "share our life here with the world," while the Syrian army launched a major offensive to retake Aleppo.

"Last message. [We are] under heavy bombardment now, we can not stay alive. When we die, keep talking about the 200,000 who are still inside. Goodbye, "Fatemah tweeted Sunday night before publishing a photograph of his daughter Bana in which she appeared to be covered in dust.

The activist news agency SMART News Agency said on Sunday that air strikes hit the al-Shaar neighborhood, where the Bana family lives, injuring at least five people.

A video shared by SMART showed people in al-Shaar walking away from the scene after the fact.

Fatemah told CNN via a direct Twitter message that her kids - Mohamed aged 5; Noor, 3, and Bana- were not injured during the bombing and his family sought refuge in a neighboring house Saturday night.

Hundreds of civilians have left the eastern part of Aleppo, controlled by the rebels, since the assault that occurred this weekend. The Syrian Observatory for Human Rights, a monitoring group based in the United Kingdom, said that the number of civilians who have left the city amounts to the thousands.

The Syrian army told state news agency SANA that its units secured evacuation routes for 1,500 people from eastern Aleppo to areas controlled by the regime on Sunday.

On Monday Bana tweeted asking people to pray in the midst of the bombings. Heavy artillery fired by regime forces continued. The Al-Shaar neighborhood remained the target of intense artillery fire by Syrian regime forces on Monday, according to activists at the Aleppo Media Center.

A local Aleppo activist said on Twitter that he knew nothing about Bana's whereabouts and his family, but that "his neighborhood had been heavily attacked."

A few hours later, Fatemah tweeted that his family was fleeing.

"We are fleeing because many people have died from heavy bombardment. We are fighting for our lives. Still with you, "said Fatemah.

"I do not want to die," is the latest message on Bana's Twitter account.