France has described the latest attack on an Aleppo hospital as "war crimes" and says the "perpetrators will be held accountable".

At least two barrel bombs hit the largest hospital in a rebel-held part of the besieged Syrian city of Aleppo, an organisation that supports it said.

The UK-based Syrian Observatory for Human Rights, which monitors the conflict, said at least one person died.

It comes three days after the hospital, called M10, was one of two struck by a heavy bombardment which left them badly damaged - an attack that UN Secretary General Ban Ki-moon also described as a war crime.

Nearby, Russian jets struck targets in rebel-held areas north of Aleppo amid a major offensive by Syria and its allies to capture the city.

Barrel bombs slam the largest hospital in the rebel-held part of Aleppo city in northern Syria https://t.co/botjxc7Qic pic.twitter.com/NyXj8hcvBw

— China Xinhua News (@XHNews) October 1, 2016

French Foreign Minister Jean-Marc Ayrault released a statement condemning the attack on the M10. He said: "In the flood of violence that overwhelms Aleppo for several days, the systematic targeting of structures and health workers is particularly unjustifiable."

"As recalled by the Secretary General of the UN, these attacks constitute war crimes. The perpetrators will be held accountable."

"This new attack only confirms the absolute urgency of a cessation of hostilities in Aleppo and access of civilian populations to humanitarian assistance they desperately need...In this very moment... France is mobilising to put a stop to this unacceptable crisis," he added.

.@MSF shocked by reports coming from east #Aleppo: 4 hospitals damaged in 4 days; trauma hospital out of service again #DoctorsOfAleppo

— MSF International (@MSF) October 1, 2016