Police turned over to prosecutors Thursday their case against four people who allegedly threw paint-filled eggs at the Fukuoka offices of two North Korean-linked groups last year.

A 34-year-old leader of a local political organization was among the four suspected of violating the Minor Offenses Law, which carries penalties of a short detention or small fine.

The offenders allegedly threw two or three eggs, each containing blue paint, at the Fukuoka offices of the pro-Pyongyang General Association of Korean Residents in Japan (Chongryun), and of Chogin-Nishi Shinkumi Bank, both located in Hakata Ward, in the early hours of May 2, police said.

The day before, the U.S. forces in Japan told the Japanese government that North Korea may have launched a short-range missile into the Sea of Japan.

Police quoted the suspects as saying they decided to take action against North Korea after learning in the news about the missile launch.