Media groups and other civil society organisations have asked government to re-open the Red Pepper and also release its directors and editors or face collective action by the media and human rights community in the country.
The groups' pronouncements at a joint media briefing in Kampala come two weeks after five Pepper Publications directors and three editors were detained.
Mr Robert Ssempala, the National Coordinator of Human Rights Network for Journalists in Uganda (HRNJ-U), who spoke on behalf of the others said human rights are entitlements and not given by the State and so must be upheld.
"Government is reminded that continued persecution and oppression of journalists is a violation of press freedom. The government should amend laws that continue to criminalise the work of journalists," he said.
They particularly hit at Uganda Communications Commission (UCC) for what they called continued media witch-hunt. They said media houses, particularly outside of Kampala, have been pressurised not to host dissenting voices.
"Every media house must be free to interview any public figure whatever their political stance and without reprisals. UCC must be seen to work for the promotion and growth of the media rather than control and curtail its freedoms," he said.
"Whether we like or agree with the content the Red Pepper publishes, this attack on press freedom undermines the freedom of all journalists to report freely on the facts. The government must stop using arrests and prosecutions as a means to intimidate journalists engaged in lawful and legitimate work," Mr Sempala said.
Other civil society organisations included Uganda Media Women Association, Chapter Four, Foundation for Human Rights Initiative, Human Rights Network, Human Rights Centre - Uganda, Hub for Investigative Media, Foreign Correspondents Association in Uganda and Centre for Public Interest Litigation, among others.
The call comes hardly a week after the United States Ambassador to Uganda, Ms Deborah Malac, described the media environment in Uganda as "increasingly threatening" and reminded government of its responsibility to "safeguard the constitutional right" to safeguard a free media.
Ambassador Malac opined that the raid on tabloid Pepper Publications and arrest and charging of its senior editors "simply for publishing an article" was uncalled for. She added that if the "government believes that media stories contain falsehoods, there are legal ways to challenge the stories."
Red Pepper directors and editors are still in detention on grounds that their freedom would endanger national security having been accused of disturbing the peace of President Museveni, Gen Salim Saleh and security minister Lt Gen Henry Tumukunde.