The World Health Organization, the International Committee of the Red Cross and Doctors Without Borders issued an "urgent call for action".

Their statement was issued 10 years after the UN Security Council unanimously adopted Resolution 2286 condemning attacks on health care facilities, medical staff and patients, they noted.

"The situation is even worse" a decade on, they said.

"As violence affecting medical facilities, transport and personnel continues unabated, the harm this resolution sought to prevent has not diminished," said the statement.

"It has continued and, in many contexts, intensified."

The three agencies said they were joining "others in the international community in issuing an urgent call for action".

They added: "When health care is no longer safe, it is often the clearest warning sign that the rules and norms intended to limit the harm of war are breaking down.

And when hospitals come under attack, "we face not only a humanitarian crisis, but a crisis of humanity. States and all parties to armed conflict must comply with the rules protecting health care."

"We urge world leaders to act and show the needed political leadership to end this violence," the statement concluded.

"Health care must never be a casualty of war."