Philippine police have arrested former president Rodrigo Duterte after the International Criminal Court (ICC) issued a warrant accusing him of crimes against humanity over his deadly “war on drugs”.

Duterte was arrested by police in Manila airport shortly after his arrival from Hong Kong.

Duterte’s brutal anti-drugs crackdown, which occured when he was president of the South East Asian nation from 2016 to 2022, saw thousands of people killed.

The 79-year-old had earlier said he was ready to go to prison, when responding to reports of his possible arrest.

The International Coalition for Human Rights in the Philippines called the arrest a “historic moment”.

“The arc of the moral universe is long, but today, it has bent towards justice. Duterte’s arrest is the beginning of accountability for the mass killings that defined his brutal rule,” said ICHRP Chairperson Peter Murphy.

But Duterte’s former presidential spokesperson Salvador Panelo has slammed the arrest, saying it was “unlawful” as the Philippines had withdrawn from the ICC.

The ICC earlier said that it has jurisdiction in the Philippines over alleged crimes committed before the country withdrew as a member.

Duterte was in Hong Kong to campaign for his senatorial slate in the upcoming May 12 mid-term elections.

Footage aired on local television showed him walking out of the airport using a cane. Authorities say he is in “good health” and is being cared for by government doctors.

Duterte, a former mayor of one of the country’s largest cities, swept to power on the promise of a widespread crackdown against crime.

With fiery rhetoric, he rallied security forces to shoot drug suspects dead. More than 6,000 suspects were gunned down by police or unknown assailants during the campaign, but rights groups say the number could be bigger.

“Hitler massacred three million Jews. Now there are three million drug addicts [in the Philippines]. I’d be happy to slaughter them,” he said a few months into office.

But critics said his “war on drugs” led to police abuse and that many of the drug suspects summarily executed.

Investigations in parliament pointed to shadowy “death squad” of bounty hunters targeting drug suspects.

Duterte has denied the allegations.

The ICC first took note of the alleged abuses in 2016 and started its investigation in 2021. It covered cases from November 2011, when Duterte was mayor of Davao, to March 2019, before the Philippines withdrew from the ICC.

Duterte cultivated an image of a tough-talking and anti-establishment man of the masses, endearing him to Filipinos who elected him as the country’s first president from the southern island of Mindanao.

His daughter, Sara Duterte, is the Philippines current vice-president and is tipped as a potential presidential candidate in 2028.

In recent months, the Duterte family’s alliance with incumbent President Ferdinand Marcos unraveled spectacularly before the public view, soon after Marcos and Sara Duterte won the 2022 elections by a landslide.

Marcos initially refused to co-operate with the ICC investigation, but as his relationship with the Duterte family deteriorated, he changed his stance, and later indicated that the Philippines would co-operate.

It is not clear yet whether Marcos would go as far as extraditing the former president to stand trial in The Hague.

Additional reporting by Virma Simonette in Manila