DAVAO CITY -- The city government is out to get the American who injured himself after an explosive in his possession went off inside his hotel room here last week.

The American, Michael Meiring, had slipped police security detailed at a hospital here Sunday and flew to Manila were he reportedly sought medical treatment for his amputated left leg and mangled right leg.

"As far as I'm concerned, I would like to throw the books at him… The crime happened here and if he is well enough to answer the charges, I suppose he has to come here and face the music," Duterte said.

The Philippine National Police (PNP) already filed on Thursday charges of illegal possession of explosives and reckless imprudence resulting to damage of property. Meiring’s room at the Evergreen Hotel here was destroyed due to the explosion.

Sr. Supt. Charlemagne Alejandrino admitted that the police did not know that Meiring left the city until after he reached Metro Manila.

He said some policemen were posted outside the door of Meiring's room in the hospital but relatives of the American berated them, forcing them to "distance themselves in such a way that they would not further antagonize" Meiring's party.

Duterte said he learned about Meiring's departure and noted the police’s failure to stop him. But he said he expects the police to bring him back to the city after he recuperates and is ready to face trial.

Aside from Duterte, agents of the Federal Bureau of Investigation (FBI) are also after Meiring.

Duterte, who met with US embassy officials at The Marco Polo Hotel on Thursday, told reporters the following day that the FBI is investigating local police reports that several US federal bank notes were found in Meiring's room at Evergreen Hotel. Duterte said it appears that the bank notes were unauthorized by the US government.

"Vis-à-vis our interests (to try him for illegal possession of explosives), the Americans are even more interested to know where those federal notes came from… because that is tantamount to economic sabotage (on the part of the US government)," he said.