There has been turmoil in Oyigbo for weeks, and a military deployment appears to have worsened the crisis.
The Rivers governor justifies ongoing military siege to an Igbo-dominated community of over 300,000 inhabitants.
The community with its over 300,000 people has seen dozens killed by soldiers since last week, even as residents run out of food and water.
Nigerian soldiers chasing members of separatist IPOB have killed dozens of residents in an Igbo-dominated community.
The revered monarch received some political leaders in the state on Saturday.
Mr. Ahmadu was accosted alongside 500 others including pregnant women while he was on his way to work.
The warning comes days after police officers were killed by suspected members of the outlawed separatist movement.
The police and the Rivers government have produced no evidence that IPOB is complicit in the recent attacks or that locals killed were IPOB members.
Weeks of separatist violence compel the governor to duplicate a federal proscription that has been in force since 2017.
There has been civil unrest in many parts of the country since the army fatally put down #EndSARS protests in Lagos on October 20.
