China is holding two Japanese men on suspicion of spying, Japanese media reported Wednesday.

One man was picked up in May near military facilities in coastal Zhejiang province and the other near the border with North Korea about the same time, Japan's leading newspapers and television stations said.

They cited unnamed sources familiar with Japan-China affairs.

Japanese government officials declined to comment.

Yoshihide Suga, the top government spokesman, told reporters that Japan does its utmost to protect citizens abroad, but that he would not discuss specific cases.

In 2010, four employees of a Japanese construction company were accused of filming a Chinese military site in Hebei province but were released within a few weeks.