Doctors Without Borders said a hospital it runs in Yemen was destroyed by Saudi airstrikes — the second attack this month on the medical charity.
The aid group — also known as Medecins Sans Frontieres (MSF) — said "several" airstrikes carried out by the Saudi-led coalition struck its facility in Saada Province beginning at around 10:30 p.m. Monday.
"Hospital staff and two patients managed to escape before subsequent airstrikes occurred over a two-hour period," it said in a statement. "One staff member was slightly injured while escaping."
The Saudi-led coalition denied its planes had hit the hospital, according to Reuters.
MSF is still reeling from a U.S. airstrike on its hospital in Kunduz, Afghanistan, which killed 30 people. The group has called for an international inquiry into the Oct. 3 attack and labeled it a possible war crime.
It said in a statement late Tuesday that it had "regularly shared" the Yemen hospital's GPS coordinates with the Saudi-led coalition and that the facility's roof was "clearly" marked with an MSF logo.
Related:Go Inside the MSF Hospital Bombed by U.S.
"The bombing of civilians and hospitals is a violation of international humanitarian law and MSF is demanding that coalition forces explain the circumstances around the attack," MSF said.
United Nations Secretary General Ban Ki-moon condemned the airstrikes and called for "prompt, effective and impartial" investigation to ensure accountability.
"The Secretary-General notes that hospitals and medical personnel are explicitly protected under international humanitarian law," Ban's spokesman said in a statement. "The Secretary-General calls on all parties to the conflict in Yemen to immediately cease all operations, including airstrikes."
The Saudi-led Arab coalition launched airstrikes in March in a bid to restore Yemen's exiled government and expel Iran-linked Houthis rebels from power.
High numbers of civilian deaths — including an airstrike on a wedding party in September which killed 131 people — have heaped criticism on the coalition and raised alarm from aid groups.
“The bombing of a hospital is shocking amid increasing reports in Yemen of civilian deaths from coalition airstrikes,” Human Rights Watch's Joe Stork said in a statement Tuesday. “Bombing a hospital sends a message that all medical facilities, health workers, and patients are at grave risk.”