The Women's League of Burma (WLB) and Mizzima Media have called for the release of women's rights activist and journalist Thin Thin Aung. Aung had been arrested in the evening on Thursday.
Myanmar is currently in the middle of a coup attempt with the military taking over a democratically elected government. Hundreds of civilians have been killed and thousands have been injured while trying to resist the move.
In a statement released on Friday, the WLB called for "concerted international action" to demand Aung's release. It said that she has been arrested and taken to the "notorious" Yay Kyi Eaing Investigation Centre.
"We are therefore extremely concerned about the life and safety of Thin Thin Aung. We urge the international community to press the military coup council for the immediate release of (the) detained women's human rights defender Thin Thin Aung and other detained activists," it said.
Mizzima Media also released a statement, mentioning that it was "deeply concerned to learn that Daw Thin Thin Aung and James Thoure, former members of Mizzima have been detained without charges."
The organisation clarified that both, Aung and Thoure, had quit the organisation formally after the coup in Myanmar. "In fact Daw Thin Thin Aung has been unwell for sometime and has withdrawn from active life and formally resigned from Mizzima in February," it mentioned.
"Mizzima fears for the lives of both its former members and appeals for their early release," it said.
Mizzima, a Burmese media organisation, came into being in August 1998 following the efforts of a group of journalists from Myanmar who were in exile in New Delhi.
The WLB release said that Aung, the founder of Mizzima News Agency and the WLB, has "dedicated her life to the fight for democracy and human rights in Burma. She has spent most of her time advocating locally and internationally for justice for women's human rights and gender equality in Burma."
Mass protests have been ongoing in Myanmar since the military seized power on February 1 with elected leader Aung San Suu Kyi, and members of her party, the National League for Democracy (NLD), among those detained. The military has taken charge and declared a state of emergency for a year.
The Myanmar military seized power on February 1 after a general election in which Kyi's NLD had won by a landslide. The army had backed the opposition who claimed there had been voter fraud and a coup happened even as a new session of parliament was about to begin.
Kyi has been held against her will, her whereabouts unknown. She is facing multiple charges. Those from her party who managed to escape have formed a new outfit while in hiding.
Military commander-in-chief Min Aung Hlaing is currently in-charge of the country's affairs.