Philippine authorities have filed charges against four people captured during a rescue mission for a Chinese-Filipino trader captive in the southern Philippines, police said Friday.

Chief Supt. Edwin Corvera, regional police commander, said they filed in court serious illegal detention against the four, who were caught inside a safe house in a village in Talon-talon on Tuesday in the southern city of Zamboanga when lawmen rescued Chinese-Filipino businessman Vinton So following a brief gun battle.

One of the suspects was identified as Arlene Sarawi, 23, who told police investigators they were framed up by their friend believed to be the mastermind.

"We have the victim's affidavit implicating them in the kidnapping," Corvera said.

The 47-year-old So was kidnapped from his junk shop on Sept. 19. Two of the suspects pretended as customers and took So at gunpoint. The kidnappers also took So's car as getaway vehicle and escaped along with the three other suspects posting as lookouts. The victim's vehicle was recovered late Sunday after the police flashed the alarm over the abduction.