The man known as "The Punisher" says he plans within days to name 27 mayors, judges and national politicians who he claims are involved in the drug trade who will not be exempt from his shoot-to-kill orders if they resist arrest.

Two mayors wept before him and pleaded to be taken off the list while two others offered to resign from their positions.

Human rights groups have called for Mr Duterte to halt the killings as the body count grows to more than 600, many of them by unknown assailants or vigilante groups.

Harrowing photographs showing bodies lying in pools of blood on the streets have gone viral on the internet, many of the victims shot at point blank range after being dragged from their homes.

Many are left with cardboard signs accusing them of being drug pushers.

In the first four days of August alone 64 alleged drug suspects were gunned down without any evidence being presented against them, 34 involving the police and 30 involving unknown assailants, according to police statistics.

Mr Duterte, the 71 year-old former mayor of Davao who was swept into office in May, told reporters that Rolando Espinosa, the mayor of Albuera on Leyte island, was lucky he surrendered at a local police station.

"I had an order to shoot him on sight like a dog….because he is treating the people of this country like dogs," he said.

"Our children have become witless."

Mr Espinosa denied he is a drug dealer but admitted his son Kerwin Espinosa was involved in the trade.

There are reports that Kerwin has fled the country.

Mr Duterte has not said how he came to the conclusion that those on the list were involved in illegal activities.

Mr Duterte acknowledged abuses in his "war on drugs" but ignored a call by the United Nations Office on Drugs and Crime to halt extrajudicial killings, which said they are "a breach of fundamental rights and freedoms."

Mr Duterte promised instead to protect police and soldiers who kill suspects.

"I will answer for the deed. If policemen are involved in encounters (with drug suspects), don't investigate it," he said.

Tens of thousands of Filipinos have surrendered to police as panic has spread over the killings, further crowding jails where in some inmates are jammed body-body on concrete floors.

Mr Duterte promised when he was sworn into office in early June that his anti-crime battle will be "relentless and sustained" and urged police to "seize the moment."

But he has not so far put forward any policy proposals on criminal justice or crime control, saying the killings are proof of the success of his campaign.

During Mr Duterte's 22 years as mayor of the southern city of Davao death squads killed hundreds of suspected criminals, drug dealers and street children as young as 14, according to an investigation by Human Rights Watch.

No charges were ever laid over the killings.

Mr Duterte said last month he is not afraid of going to jail, as he was aged 71, but added that as president he has immunity from prosecution.

Sixteen million Filipinos voted for Mr Duterte after he campaigned vowing to kill suspected drug dealers and other criminals and that fish in Manila Bay would grow fat on the bodies.