BISHKEK -- Police in Bishkek have detained four men suspected of assaulting Bolot Temirov, the editor in chief of Kyrgyz investigative website FactCheck.

The Interior Ministry said that the suspects, whose identities were not disclosed, were detained on January 14 and charged with assault and robbery.

According to the ministry, the suspects were between the ages of 26 and 28.

Temirov was attacked near his website's office in Bishkek on January 9.

The assailants took his mobile phone away.

The United States and several media-freedom watchdogs have called on Kyrgyz authorities to conduct a swift and thorough investigation into the case.

In December, the FactCheck website was hacked along with sites of several online news resources that used FactCheck's material.

FactCheck mainly investigates corruption among state officials.

Temirov's site and open-source investigative organization Bellingcat recently probed Raimbek Matraimov, the former deputy chief of Kyrgyz customs, and his relatives, who are at the center of an alleged corruption scandal involving the funneling of close to a billion dollars out of Kyrgyzstan.