President Rodrigo Duterte on Tuesday said female fighters should not bear children while still with the New People's Army because they "multiply the problem."

"Sabi ko, hoy kayong mga Amazona, kung magrebelde lang naman kayo, 'wag kayong manganak, because you multiply the human problem," Duterte said.

NPA is the armed wing of the Communist Party of the Philippines.

Duterte also explained that his remark about shooting female fighters in the genitals was made to threaten and insult them.

"Sabi ko, bantay kayo, sabihin ko sa sundalo barilin 'yung ****** ninyo. Pantakot. Pang-insulto, if you want. Kasi galit talaga ako," the president said in a speech during the general assembly of the League of Municipalities of the Philippines.

• Duterte defends 'sarcastic' remark on shooting women in genitals

Women's group Gabriella had called Duterte "the most dangerous macho-facist in government" and said his remark "openly encourages violence against women and contributes to impunity on such."

Meanwhile, Human Rights Watch researcher Carlos Conde said Duterte's remark was "just the latest in a series of misogynist, derogatory and demeaning statements" about women that encouraged state forces to commit sexual violence.

• Roque: Don't take Duterte literally