MANILA – A left-wing human rights organization accused the Philippine security forces of killing nine activists in coordinated raids in four provinces on Sunday.

Cristina Palabay, the leader of the Karapatan rights group, said the raids were carried out on the activists’ homes and offices. Two of the victims, a couple, were killed while their 10-year-old son was hiding under a bed, she said.

A government spokesman could not be immediately reached for comment, but a security official confirmed that nine people were killed in raids carried out jointly by the military and the Philippine National Police. He spoke on condition of anonymity because he was not authorized to discuss the matter.

Filipino outlet GMA News said a police spokesman, Lt. Col. Chitadel Gaoiran, had confirmed the death.

Ms. Palabay said the killings took place in Cavite, Laguna, Batangas and Rizal provinces in the southern part of Luzon Island near Manila. She said the activists who were killed worked for a variety of organizations, including a group that works for Filipino fishermen and another that campaigned for the rights of the urban poor.

“Nothing could be more appropriate than calling this day a ‘bloody Sunday’,” Ms Palabay said in a statement. She said the killings were part of a “grueling campaign of state terror” by President Rodrigo Duterte’s administration to quell legitimate dissent, and she called on the country’s independent human rights commission to investigate the raids.

Three activists were arrested in the raids, including a paralegal who worked for Karapatan, Ms. Palabay said.

Mr Duterte and other prominent Filipino officials, including military and police commanders, have accused Karapatan and other left-wing groups of having links to a longstanding communist uprising in the country. Karapatan and similar groups have denied involvement in violence.

Phil Robertson, deputy Asia director for Human Rights Watch, said his organization was “seriously concerned” by reports of the raids, which were “clearly” part of the government’s counterinsurgency campaign against communist rebels.

“The fundamental problem is that this campaign no longer makes the distinction between armed rebels and non-fighting activists, union leaders and legal defenders,” Robertson said in a statement.

On Friday, two days before the raids, Mr. Duterte called on the Filipino security forces to kill communists in combat. “I have told the military and police that if they are in an armed encounter with the communist rebels, kill them, make sure you really kill them and take them out if they are alive,” he said.

The Communist Party of the Philippines issued a statement calling on its armed wing, the New People’s Army, which has been rioting since 1969, to punish “the perpetrators and masterminds” behind the reported raids.