Freelance correspondent Ben Bohane goes on patrol with police and the media in Manila to document Philippines President Rodrigo Duterte's war on drugs.

Warning: This story contains graphic images

I had been enjoying the hospitality of Manila's night-crawling media and police photographers at their base for barely 20 minutes when the first call came through.

Jumping into a convoy of cars at the city's police headquarters in Ermita, we moved at speed through the tangle of traffic, racing to document the next killing in the Philippines' "drug war".

It was 11:00pm and the dozen photographers from local media, such as the Manila Bulletin and Philippine Star, and wire agencies, had already covered one slaying earlier in the evening.

Filipino media at Manila's police headquarters watching television, playing cards and singing as they wait to be called out to the next crime scene. ( ABC News: Ben Bohane )

"Last night there were 12 killings around Manila," one says. "Most nights recently there are at least 10."

We head to Marikina City in north-west Manila and find a crime scene being established by police. A body lies in an alley next to a convenience store.

As we wait for permission to go under the yellow tape and photograph, we get the next call — a shoot-out nearby.

"Let's hop to the next one — it is an ex-cop who has been killed, so it will be more interesting," freelance photographer Linus Escandor says.

Racing through the streets of Manila to another crime scene, Filipino media and police photographers travel in a convoy of vehicles. The group must move quickly before investigators close off access. ( ABC News: Ben Bohane )

Fifteen minutes later, we are at the next scene. There, spread-eagled with gruesome head wounds and a trail of blood, lies the former police officer, dead.

He had been killed in a shoot-out with officers from the Station Anti-Illegal Drugs Special Operations Task Group during a midnight raid, 25 minutes earlier.

The man was identified as Pelito Basan Obligacion, an alleged drugs and guns dealer — and like most cases — had supposedly "fired first, causing police to respond".

A Colt 45 pistol lay near his limp hand.

Police secure a crime scene where a drug runner was killed in Marikina City, in the north-west of the Philippines capital, Manila. ( ABC News: Ben Bohane )

The scene is ablaze with headlights, flashing police lights and TV camera lights, as forensics teams go to work — once the photographers have got their shots.

Yellow tape then cordons off the area, spent bullet casings are circled in chalk and numbered.

"Most of the killings happen in the outer suburbs or central Manila, not so much in Makati [the main business district] because there is a lot of CCTV there," Linus says.

Police at the scene where an alleged drug runner, who was also a former policeman, was shot dead by police in Quezon City. ( ABC News: Ben Bohane )

Addicts race to rehab

The killings began before Mr Duterte had even been sworn into office, as if in anticipation.

Two weeks after his inauguration, 200 drug dealers and users have been killed in shoot-outs in the withering crackdown where police have a licence to "shoot first, ask later".

About 60,000 addicts have handed themselves in for treatment at clinics around the country in recent weeks, fear now overriding hardcore addiction.

A chalk circle marks a spent bullet casing at a crime scene. ( ABC News: Ben Bohane )

In 2012, the United Nations said the Philippines had the highest rate of methamphetamine use in East Asia.

According to a US State Department report, 2.1 per cent of Filipinos aged 16 to 64 use the drug, known locally as "shabu shabu".

Chinese triads have been accused of importing it from China and meth labs have reportedly been operating in prisons, implicating jail wardens.

Last week Mr Duterte named and shamed five of the nation's highest police chiefs as "narco-generals", who protect criminal syndicates.

More than 120 officers have been sacked in one province alone, the Visayas region, according to the Philippine Enquirer.

Mr Duterte has even enlisted the willing help of the New People's Army — the communist insurgents — to take out drug dealers in their areas.

The Philippines leader has vowed to risk everything to put an end to the drug problem, which he says is a major security and corruption issue.

A former mayor of Davao, on Mindanao, he is credited with creating one of the safest cities in the country with his tough-on-crime approach, although critics have denounced his vigilante-style methods.

In a recent speech, Mr Duterte summed up his stance: "If you destroy my country, I will kill you. If you destroy our children, I will kill you. If I am asked by anybody, including the Commission on Human Rights, I do not know you".

Not only legal and human rights organisations, but ordinary Filipinos who voted for him are alarmed by what they see as a war on drugs, that is also a war on poor people.

A taxi driver, Bobby, says he voted for Mr Duterte, but told me:

"We have courts for a reason. You can't let cops be judge, jury and executioner."

President Duterte has previously vowed to "kill all drug traffickers". ( Supplied: Linus Escandor )

Summary executions common in drug war

In the early hours back at the station, the police and general media are smoking and strumming guitars when a fourth call-out comes.

This one is a "salvage job" — slang for a summary execution — so named because the victims are often wrapped in plastic and dumped.

A supporter of Philippines' presidential frontrunner Rodrigo Duterte at a campaign rally, May, 2016. ( ABC: Adam Harvey )

The local media refer to these as vigilante killings, often aimed at silencing potential informers. But according to Linus, not all of them deploy the "salvage job" approach.

"They can't be bothered wrapping them in plastic. They just shoot them and say there was a shoot-out," he said.

Once again we are speeding through the traffic, heavy for this time of night. This is actually the most dangerous part of the job, as usually the press and police photographers arrive after the killings and there is not much risk.

But the rush to get to a crime scene and document it before police cordon it off and remove the body and the evidence, is the riskiest part, as I soon discover.

Changing lanes in light rain, a taxi brakes hard in front of us and suddenly we are fishtailing and nearly slam into buildings on the sidewalk.

At that point, it is after 3:00am and back at the station I decide to call it a night, leaving the photographers waiting for the next macabre scene, as the bodies in Mr Duterte's drugs war keep piling up.