TOKYO, Japan-A military drill on island defense was launched Sunday by Japan’s Self-Defense Forces (SDF) in the city of Narashino in Chiba Prefecture, reports say.

About 20 aircrafts and 33 armored vehicles joined in the war game, according to Xinhua, the official newspaper of the People’s Republic of China.

According to the report, Japanese Defense Minister Itsunori Onodera said the military drill was to ensure Japan’s security as its neighboring countries like Democratic People’s Republic of Korea intensified its military modernization and rocket testing.