Offensive by President Bashar al-Assad triggered the single biggest displacement of the bloody seven-year war

By Heba Kanso

BEIRUT, July 19 (Thomson Reuters Foundation) - An estimated 55,000 Syrian children are cut off from aid and risk starvation after an offensive by President Bashar al-Assad triggered the single biggest displacement of the bloody seven-year war, humanitarian organisations said on Thursday.

Government forces backed by Russian air power have swept through southwestern Syria in the last month in one of the swiftest campaigns of a war estimated to have killed hundreds of thousands of people and displaced 11 million.

The offensive has put an estimated 55,000 children in al-Quneitra province near the border with the Israeli-occupied Golan Heights at risk of death without life-saving aid, said the United Nations children's agency (UNICEF).

"This is life or death for these children - they are being subjected to air strikes, barrel bombs and being cut off from humanitarian aid," said Caroline Anning spokeswoman for the charity Save the Children by phone from Amman, Jordan.

Within the last few weeks the charity has heard of children dying and getting sick from drinking dirty water, dehydration and scorpion and snake bites, Anning told the Thomson Reuters Foundation.

The U.N. has warned of a humanitarian catastrophe in the southwest caused by the fighting that erupted after a Russian-backed army offensive to recapture rebel-held southern Syria.

The offensive has triggered the single biggest displacement of the war with 270,000 forced to flee their homes in southwestern Syria as a result of the escalation of fighting this month, according to the U.N. refugee agency (UNHCR).

"What concerns us are the restrictions on the humanitarian access - it is unacceptable," said Juliette Touma, a UNICEF spokeswoman in Amman.

Save the Children and its local partners have given Syrian children identity bracelets in case they are split from their families during these "mass displacements" said Anning.

"It is a really depressing cycle that keeps happening in Syria. We are urging for a ceasefire, for humanitarians to be able to continue their work, and for aid convoys to be able to get in to this area," she said.

(Reporting by Heba Kanso @hebakanso, Editing by Claire Cozens. Please credit Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights, and climate change. Visit www.trust.org)

Our Standards: The Thomson Reuters Trust Principles.