A group of 50 doctors and medical professionals from across the globe have called for the UN to provide more support to medical personnel caring for Syrians in need, warning that the country's health systems are at "breaking point", and urging Syrian authorities to immediately lift restrictions that are preventing doctors and medicines from reaching patients.

In an open letter, published in The Lancet just ahead of this month's United Nations (UN) General Assembly, the high-profile group of signatories - which includes several Nobel prize winners, and a former Director-General of the World Health Organization, from countries including the UK, US, Russia, India, and Turkey - write that they are "horrified" by the scale of the emergency in Syria, calling it "arguably one of the world's worst humanitarian crises since the end of the Cold War."

The signatories highlight the acute shortage of medical personnel, supplies, and facilities afflicting the people of Syria after more than two years of conflict, with over half of Syria's hospitals destroyed or damaged, and thousands of health workers either imprisoned, or fleeing abroad.

"As doctors and health professionals we urgently demand that medical colleagues in Syria be allowed and supported to treat patients, save lives, and alleviate suffering without the fear of attacks or reprisals," say the authors.

"Governments that support parties to this civil war should demand that all armed actors immediately halt attacks on medical personnel, facilities, patients, and medical supplies and allow medical supplies and care to reach Syrians, whether crossing front lines or across Syria's borders. We call on the UN and international donors to increase support to Syrian medical networks, in both government and opposition areas, where, since the beginning of the conflict, health professionals have been risking their lives to provide essential services in an extremely hostile environment."