Nine local staffers for Doctors Without Borders were killed and 30 were missing after an explosion near their hospital in the northern Afghan city of Kunduz that may have been caused by a U.S. airstrike.
In a statement, the international charity said the "sustained bombing" took place at 2:10 a.m. (2140 GMT). Afghan forces backed by U.S. airstrikes have been fighting to dislodge Taliban insurgents who overran Kunduz on Monday.
U.S. forces in Afghanistan said they conducted an airstrike on Kunduz at 2:15 a.m. The spokesman, U.S. Army Col. Brian Tribus, said the strike "may have resulted in collateral damage to a nearby medical facility" and that the incident was under investigation. Tribus said it was the 12th U.S. airstrike "in the Kunduz vicinity" since Tuesday.
Doctors Without Borders said its trauma center "was hit several times during sustained bombing and was very badly damaged." At the time of the bombing, the hospital had 105 patients and their caretakers, and more than 80 international and Afghan staff, it said.
Interior Ministry spokesman Sediq Sediqqi said 10 to 15 "terrorists" had been hiding in the hospital at the time of the strike. "All of the terrorists were killed but we also lost doctors," he told a press conference. He said 80 staff at the hospital, including 15 foreigners, had been taken to safety.
Doctors Without Borders said all of its international staffers were alive and accounted for. It said it regularly updated its GPS coordinates with all parties to the conflict.
Adil Akbar, a doctor at the trauma center who was on duty at the time, told The Associated Press that the operating theater, emergency room and other parts of the hospital complex had been hit in the bombing.
"I managed to escape after the attack but I know that most of the staff and even some of the patients are missing," he said.
Zabihullah Pashtoonyar, a former local radio reporter who was working as a security guard at the compound, was one of those killed in the incident, said his relative Gul Rahim.
The number of dead and missing was provided by the charity.
Wahidullah Mayar, spokesman for the Public Health Ministry, tweeted that 37 people were wounded, among them 24 medical and non-medical staff.
Bart Janssens, the charity's director of operations, said "we do not yet have the final casualty figures," adding that the group's medical team was treating wounded patients and staffers.
Nicholas Haysom, the U.N. special representative in Afghanistan, condemned the "tragic and devastating airstrike" on the hospital. "I reiterate my call on all parties to the conflict to respect and protect medical and humanitarian personnel and facilities," he said in a statement.
The International Committee of the Red Cross, which also has facilities in Kunduz, said it was "deeply shocked."
Doctors Without Borders said it had treated 394 people wounded in fighting since the Taliban attacked the city. Afghan forces went in on Thursday, and the fighting has been underway since then.
Sediqqi said Afghan forces were still sweeping the city for militants, conducting "meter to meter, house to house operations" that would continue until "all those bad elements" had been eliminated.
Taliban spokesman Zabihullah Mujahid issued a statement saying there were no Taliban fighters in the hospital at the time of the bombing. It accused Afghanistan's intelligence service of misdirecting the airstrike to purposefully hit the hospital.
The clinic in Kunduz is a sprawling facility with numerous buildings situated in the east of the city, in a residential area close to the local office of the NDS intelligence service.
Another Kunduz resident, Dawood Khan, said a cousin who works at the clinic as a doctor was lightly wounded in the bombing.
"I heard the sound of the bomb and rushed to the hospital to get news. The operating theater was on fire, people were terrified, running everywhere," he said.
Electricity and water have been cut off since the Taliban's Monday assault and seizure of the city, officials and residents said. Food and medical supplies cannot get through because the Afghan military is still working to clear mines planted by the Taliban. Sporadic gunfights are continuing in various pockets of the city as troops advance.
Most of the Taliban appear to have fled the city after the troops moved in on Thursday, taking looted vehicles, weapons and ammunition with them.
Officials have reported that they have moved east, into Takhar and Badakhshan provinces, where a number of districts fell to the Taliban on Friday. The Defense Ministry said troops had retaken the Baharak district after retreating under fire Friday.
The U.S. Embassy in Kabul issued an emergency notice to Americans in Badakhshan, saying they should "consider departing the area immediately."
Associated Press writers Rahim Faiez and Humayoon Babur in Kabul, Afghanistan, contributed to this report.