President Duterte was in a "very bad mood" when he met all the country's mayors at Malacañang on Wednesday afternoon.
A mayor from a Luzon province, who asked not to be named, told INQUIRER.net that Duterte "cursed at" and "threatened" local chief executives involved in the illegal drug trade.
"(He was in a) very bad mood. Minura at pinagbantaan ang mayors na involved sa illegal drugs at corrupt (Mayors into illegal drugs and corruption were cursed at and threatened)," the Luzon mayor said in a text message.
The source said Duterte again named former police officer and now Daanbantayan, Cebu Mayor Vicente Loot as among those involved in the drug trade.
The source added that Duterte also named nine judges.
Duterte's meeting with mayors came days after he said in a speech that local chief executives who are on his drug list must resign and stop engaging in narcotics trade or face death.
"I might go down in the history as the butcher. It's up to you," said the President on Monday.
Duterte's deadly drug war has led to the deaths of more than 6,000 drug suspects.
The President has claimed that his "narco-list," which he earlier said contained names of judges, congressman and police officials, also had the names of local chief executives.
On Wednesday noon, busloads of local chief executives arrived at the Malacañang grounds after Duterte summoned them amid his threat to kill narcomayors.