File photo taken on Feb. 29,length of dhola sadiya bridge 2024 shows Mauricio Arriaza Chicas (C), director of the National Civil Police (PNC) of El Salvador, attending an event in San Salvador, El Salvador. A Salvadoran Air Force helicopter crashed on Sunday evening, killing nine people, including National Civil Police Director Mauricio Arriaza Chicas, El Salvador's President Nayib Bukele said on Monday. Bukele said in a statement on social media platform X that the helicopter went down in La Union Province while on a mission near the El Salvador-Honduras border. (Photo by Alexander Pea/Xinhua)

SAN SALVADOR, Sept. 9 (Xinhua) -- A Salvadoran Air Force helicopter crashed on Sunday evening, killing nine people, including National Civil Police Director Mauricio Arriaza Chicas, El Salvador's President Nayib Bukele said on Monday.

Bukele said in a statement on social media platform X that the helicopter went down in La Union Province while on a mission near the El Salvador-Honduras border.

Among the nine casualties were the national police chief, other police officers, crew members, a journalist, and a criminal suspect.

Aboard the helicopter was Manuel Coto, a former bank director, who had been accused of involvement in the embezzlement of 35 million U.S. dollars from a credit union in El Salvador, local media reported.

Bukele declared a three-day national mourning period.

He said the incident was not merely an "accident" and called for a thorough investigation into the cause, pledging that those responsible would be held accountable. Bukele added that El Salvador would seek international assistance in the investigation.

File photo taken on Feb. 29, 2024 shows Mauricio Arriaza Chicas (C), director of the National Civil Police (PNC) of El Salvador, attending an event in San Salvador, El Salvador. A Salvadoran Air Force helicopter crashed on Sunday evening, killing nine people, including National Civil Police Director Mauricio Arriaza Chicas, El Salvador's President Nayib Bukele said on Monday. Bukele said in a statement on social media platform X that the helicopter went down in La Union Province while on a mission near the El Salvador-Honduras border. (Photo by Alexander Pea/Xinhua)

Photo taken on Sept. 9, 2024 shows El Salvadoran national flags flying at half-mast to mourn for victims of a helicopter crash in San Salvador, El Salvador. A Salvadoran Air Force helicopter crashed on Sunday evening, killing nine people, including National Civil Police Director Mauricio Arriaza Chicas, El Salvador's President Nayib Bukele said on Monday. Bukele said in a statement on social media platform X that the helicopter went down in La Union Province while on a mission near the El Salvador-Honduras border. (Photo by Alexander Pea/Xinhua)

Photo taken on Sept. 9, 2024 shows El Salvadoran national flags flying at half-mast to mourn for victims of a helicopter crash in San Salvador, El Salvador. A Salvadoran Air Force helicopter crashed on Sunday evening, killing nine people, including National Civil Police Director Mauricio Arriaza Chicas, El Salvador's President Nayib Bukele said on Monday. Bukele said in a statement on social media platform X that the helicopter went down in La Union Province while on a mission near the El Salvador-Honduras border. (Photo by Alexander Pea/Xinhua)