Deliberate attacks on hospitals amount to “war crimes,” UN Secretary-General Ban Ki-Moon said just hours after a hospital was targeted in the Syrian city of Aleppo.

“Let us be clear: Intentional and direct attacks on hospitals are war crimes. Denying people access to essential health care is a serious violation of international humanitarian law,” Ban said in a speech to the UN Security Council in New York. “When so-called surgical strikes end up hitting surgical wards, something is deeply wrong.”

The United Nations Security Council unanimously adopted a resolution late on Tuesday condemning attacks on medical facilities and humanitarian personnel in Syria.

The resolution was adopted by the 15-nation council after foreign-backed militants launched an assault in Aleppo and fired rockets on a hospital.

Under international law, any intentional attack against hospitals and places where the sick and wounded are collected already is considered a war crime.

The British-based Syrian Observatory for Human Rights said militant rockets had killed 19 people in government-held territory, including an unspecified number at the al-Dabit hospital.

There have also been reports of airstrikes blamed on the Syrian government against hospitals in Aleppo but Damascus has denied those allegations and pointed the finger at the US and its allies.

International President of Doctors without Borders (MSF) Joanne Liu told the council that hospitals must not be attacked or forcibly entered by warring sides.

“Medical ethics cannot be buried by war,” Liu said, adding, “In Afghanistan, the Central African Republic, South Sudan, Sudan, Syria, Ukraine and Yemen, hospitals are routinely bombed, raided, looted or burned to the ground.”

She said that precise attacks on hospitals are described by perpetrators as “mistakes, or denied outright, or are simply met with silence,” calling on all countries to “stop these attacks.”

“In reality, they amount to massive, indiscriminate and disproportionate civilian targeting in settings. In the worst cases, they are acts of terror,” Liu said.

More than 730 medical workers have been killed since Syria’s civil war began five years ago and there have been more than 360 attacks on some 250 medical facilities in the country, according to Physicians for Human Rights, a nonprofit that uses forensic science, clinical medicine, and public health research to document human rights abuses.