A governance group, Coalition for Revolution (CORE), says despite the repressive moves by the President Muhammadu Buhari regime in trying to stop its planned symposium scheduled to hold today (Monday).
It said Buhari's intolerance towards opposition had continued to increase by the day.
A statement by the group said: "In the early hours of this morning, a combined team of police, military, and DSS invaded and sealed off the venue of our National Discourse (symposium) scheduled to hold by 11am this morning of Monday, August 19, 2019.
"The owner of the event centre was denied access to his property and the whereabouts of the resident staff of the event place are now unknown. Innocent bystanders are being harassed and arrested in a Gestapo manner.
"This is a panicky response of a so-called civilian government to Citizens National dialogue on the state of the Nation. No wonder the country is sinking deeper into crises and anarchy.
"We remain focused and determined not to let anyone take away our rights to speech and association."
The group added: "We have paid for the venue and are determined to go on with the programme as scheduled for 11 am today.
"The whole world can now see the true face of this government and appreciate the reason why we demand that there must be a change in the way things are being done in the country.
"We are, however, resolute and unshaken in our resolve to change the prevailing oppressive political system in Nigeria."