Aung Kyaw is the third DVB journalist imprisoned since the military's 1 February of Aung San Suu Kyi's elected government, which caused nationwide outrage and daily protests, some of which were suppressed by troops using live ammunition.
Mizzima said Zaw Zaw was one of six of its staff arrested since the coup.
DVB and Mizzima are among several news outlets that have had licenses revoked by the junta, which has restricted internet access and banned outside satellite broadcasts in an effort to stifle opposition to its rule.
A spokesman for the military council could not be reached for comment on Wednesday. The junta has said it respects the media but will not tolerate journalists who instigate unrest.
The military has in recent months arrested then deported a Japanese and a Polish journalist and is currently holding two American media workers.
The US deputy secretary of State Wendy Sherman on Wednesday said the US had pressed the military to release Americans Daniel Fenster and Nathan Maung and that she had raised their arrests with other countries in the region.
"The detention of Daniel and Nathan, as well as the use of violence by the Burmese military to other journalists, constitutes an unacceptable attack on the freedom of expression in Burma," Sherman said in a call with media in Bangkok, referring to Myanmar by its former name.
The military, which ruled Myanmar from 1962 to 2011, has struggled to consolidate power since the coup and has met opposition in multiple forms, from peaceful street protests and western sanctions to deadly ambushes on troops by volunteer militias.