Warplanes level a hospital in the rebel-held half of Aleppo, Syria, killing one of the city’s last pediatricians. A Saudi-led military coalition bombs a hospital in Yemen. In Afghanistan, American aircraft pummel a hospital mistaken for a Taliban redoubt.

The rules of war, enshrined for decades, require hospitals to be treated as sanctuaries from war — and for health workers to be left alone to do their jobs.

But on today’s battlefields, attacks on hospitals and ambulances, surgeons, nurses and midwives have become common, punctuating what aid workers and United Nations officials describe as a new low in the savagery of war.

On Tuesday, the Security Council unanimously adopted a resolution to remind warring parties everywhere of the rules, demanding protection for those who provide health care and accountability for violators. The measure urged member states to conduct independent investigations and prosecute those found responsible for violations “in accordance with domestic and international law.”