A group of 36 Japanese men have been detained in Manila over an alleged phone scam targeting people in Japan, Philippine immigration sources said Thursday.

Based on information from Japanese investigative authorities, the immigration bureau detained the men at a hotel in Manila on Wednesday afternoon and transferred them to detention facilities, the sources said.

The group is believed to have operated from multiple locations in the Philippines, the sources said.

Four Japanese suspected of involvement in the scam were arrested by Tokyo police earlier after returning to Japan, according to Japanese investigative sources.

In a separate case, Japanese police arrested 15 Japanese earlier this year for alleged involvement in a phone scam targeting people across Japan that was operated out of a rented luxury house in the Thai beach resort of Pattaya.