A group of journalists in Japan called on Myanmar's junta to free one of their colleagues on Tuesday (April 20).
Yuki Kitazumi was detained in Yangon Sunday evening by military outside his home for allegedly "spreading falsehoods".
Isoko Mochizuki, a long-time friend of Kitazumi, is part of a group of journalists who started an online petition on Monday (April 19) addressed to Myanmar's junta and the Japanese government, calling for Kitazumi's release.
"We want the junta to stop oppressing the citizens of Myanmar, and we seek the swift release of the many detained journalists, including Kitazumi, who strove to tell the truth. Although we are far away, I hope the media in Japan can also speak out and that's why we put out a statement on Change.org and held this news conference today."
So far, 2,000 people have signed the petition.
The director of Human Rights Watch in Japan Kanae Doi accused the Japanese government of not putting enough pressure on Myanmar.
Meanwhile, Japanese chief cabinet secretary Katsunobu Kato told a briefing on Tuesday that the government is seeking an early chance to visit the journalist and demands for his quick release.
Kitazumi runs a media production company, and used to be a journalist with the Nikkei business daily.
He was arrested previously in February while covering protests in Myanmar but was released soon afterwards.