Myanmar's security forces forcibly entered the homes of Japanese diplomatic and aid staff in the country's largest city Yangon in April, a Japanese government source said Sunday.

The security forces were apparently trying to search the premises of pro-democracy forces that oppose the military, but they withdrew once they learned the occupants were Japanese, the source said. The occupants were not harmed.

In Yangon lodged a protest with Myanmar authorities, citing a violation of the Vienna Convention on Diplomatic Relations, which stipulates the protection of diplomats from arrest or detention, and inviolability of mission premises.