Families of drug war victims celebrated on Tuesday after former strongman president Rodrigo Duterte was arrested for alleged crimes against humanity.

The relatives, holding up placards and signs as they demanded justice for their loved ones, marched on the streets of Quezon City in Manila to mark Duterte's arrest on March 11.

Teddy Casino, chair of the political party-list Bayan Muna that participated in the rally, said in a statement: 'Finally, he will be held to account before a court observing due process - something which he denied thousands of victims of his bogus drug war.'

Duterte was arrested on March 11 morning at the Ninoy Aquino International Airport on a warrant issued by the International Criminal Court (ICC) for alleged crimes against humanity.

He had initially refused to disembark the plane upon arrest, telling officials: 'You will just have to kill me. I refuse if you will just ally with the whites.'

He was later seen boarding a police vehicle with his wife Honeylet Avancena and daughter Veronica. He was then flown to The Hague.

Duterte had returned to the country on Cathay Pacific flight CX907 after meeting with overseas Filipino workers in Hong Kong a day earlier.

Philippine President Ferdinand Marcos Jr., a former ally and now political rival of the influential Duterte family, defended the government's role in Duterte's arrest.

He said: 'Interpol asked for help and we obliged because we have commitments to Interpol which we have to fulfil. If we don't do that, they will no longer help us with other cases involving Filipino fugitives abroad. We cannot say no to Interpol when they ask us to catch a wanted individual.'

Duterte is the architect of the country's notoriously bloody war on drugs, which police claimed saw more than 6,000 drug suspects killed. However, human rights groups said the alleged extrajudicial executions reached up to 30,000.

In 2018, he withdrew the Philippines from the International Criminal Court (ICC) after it began investigating alleged human rights abuses linked to his war on drugs. He had argued that the ICC had no jurisdiction over the Philippines and accused it of being biased.