YANGON -- A Japanese minister met Myanmar's military rulers on Monday to try to persuade them to free pro-democracy leader Aung San Suu Kyi, a Japanese diplomatic source said.

International anger with the generals has mounted since they detained the Nobel peace prize winner on May 30 after a clash between her supporters and a pro-junta group.

Japan, the main aid donor to the impoverished country formerly known as Burma, sent its Deputy Foreign Minister, Tetsuro Yano, to meet Myanmar's military intelligence chief Khin Nyunt, third in command in the junta, the source said.

He said Myanmar's foreign minister, Win Aung, attended the meeting, but gave no further details. Yano, who was in Yangon for just a few hours and was scheduled to leave later on Monday, also separately met Home Minister Tin Hlaing, the source said. Japan said last week it would consider scaling back assistance to Myanmar if Suu Kyi is not released.

The Myanmar junta has said it is holding Suu Kyi for her own personal safety and says it will free her soon.

Former colonial power Britain says Suu Kyi is being held in the "notorious" Insein Jail, the biggest prison in the British empire before 1945, on the northern outskirts of Yangon, Reuters reported.

A six-member team from the International Committee of the Red Cross left Yangon on Sunday to see around a dozen leaders of Suu Kyi's National League for Democracy (NLD) believed held in the Mandalay area in central Myanmar.

But the team's leader, Michel Ducreaux, told Reuters last week the junta had denied access to Suu Kyi.

The NLD swept to a landslide election victory in 1990 but has been prevented from taking power by the military, which has ruled Myanmar in various guises since a 1962 coup.