A man has been arrested in Kodaira, western Tokyo, for allegedly choking his girlfriend to death in the apartment they were living in last week, the police said.

Shunichi Kono, 25, admitted killing nurse Rika Takagi, 24, but said he doesn't want to talk about his motives until his feelings are organized, the police said Sunday night.

The two had been living together for about 1½ years, but Takagi recently told her friends she wanted to break up, which investigators suspect triggered the violence. Kono allegedly killed Takagi between Thursday and Friday.

The police arrested Kono on Sunday morning after tracking him down in Atami, Shizuoka Prefecture.

Records say Takagi left the hospital after her shift ended Thursday morning but failed to appear for her next shift Friday evening. When she did not answer her mobile phone, her supervisors called the police.

Takagi's naked body was found Friday night in an empty bathtub. An autopsy showed she had been strangled to death a day or two before.

The door and windows of the apartment were locked and her clothes were found on the floor.