SANA, Yemen — At least 15 people were killed on Monday in northern Yemen when warplanes bombed a hospital supported by Doctors Without Borders, according to hospital and local health ministry officials.

The airstrike hit Abs Hospital in Yemen’s northern Hajjah Province, and three Yemeni staff members of Doctors Without Borders were among the dead, said the hospital director, Ibrahim Aram, who was reached by telephone. He said that three foreign doctors at the hospital were also wounded, and that three other staff members had limbs amputated.

The bombing came two days after Saudi airstrikes killed at least 19 people, mostly children, in a residential area and a school in northern Yemen.

The Saudi-led coalition fighting Houthi militias has stepped up its bombing campaign in recent weeks after peace talks collapsed between the rebels who control the capital, Sana, and the largely exiled government of President Abdu Rabbu Mansour Hadi, which is backed by the coalition and by Western powers.

Ayman Ahmed Mathkoor, the health director for Hajjah Province, said the airstrike on Monday had destroyed the emergency department of Abs Hospital, killing 15 people and wounding 20.

In a news release on Monday afternoon, Doctors Without Borders — often known by its French name, Médecins Sans Frontières — said that at least 11 people, including a member of the organization’s staff, had been killed in the attack on the hospital, and 19 wounded. Nine people were killed immediately, and two more died while being moved to another hospital, according to the news release. Mr. Aram said he was unsure how many patients had died.

Hospitals in Yemen supported by Doctors Without Borders have been hit by coalition airstrikes at least four times in the country’s 17-month war. Saudi officials have insisted that they have struck only at military targets, and have accused the Houthis of using civilian facilities to carry out attacks against the government and its coalition partners.

Ban Ki-moon, the United Nations secretary general, condemned the attack in a statement, emphasizing that antagonists in the Yemen conflict had damaged or destroyed more than 70 health facilities since the hostilities began 17 months ago.

Ibrahim Jafari, a health ministry official who went to the hospital on Monday, said the emergency room had been full of patients when it was hit. Many of the victims were badly burned, he said, and body parts were scattered around the site. Mr. Jafari said there were no military forces near the hospital.

The nearest military activity involving the Houthi militias was more than 35 miles away, he said.

Amnesty International in the United States condemned the attack, and an Amnesty official said in a statement that the targeting of medical facilities could constitute “a serious violation of international humanitarian law, which would amount to a war crime.”

Mr. Aram, the hospital director, said the three Doctors Without Borders staff members who were killed were a guard, a logistician and an electrician. In addition, another guard, an X-ray technician and a nurse had limbs amputated because of their wounds, he said, adding that the three foreign doctors had relatively minor injuries.

“Today’s airstrike appears to be the latest in a string of unlawful attacks targeting hospitals, highlighting an alarming pattern of disregard for civilian life,” said Magdalena Mughrabi, an Amnesty official.

Other hospitals supported by Doctors Without Borders that are known to have been hit in Saudi strikes include Shiara Hospital in Razeh, in Sada Province, struck on Jan. 10; Taiz Hospital in the city of Taiz, struck on Dec. 2; and Haydan Hospital in Haydan, Sada Province, struck on Oct. 26, according to statements from the aid organization as well as government health officials.

Mr. Aram said that Doctors Without Borders had not begun supporting Abs Hospital until it was assured that the Saudi coalition was aware of the hospital’s geographical coordinates, in line with the organization’s longstanding policy for hospitals in war zones.

Maj. Gen. Ahmed Asseri, the spokesman for the Saudi-led coalition, said a statement about the airstrike would be issued. Efforts to reach spokesmen for the Yemeni government supported by the Saudi coalition were unsuccessful.