IPOB, which claimed to have set up the Eastern Security Network (ESN), said no other vigilante group would be allowed in the region.
The group, in a statement by its spokesman, Emma Powerful, claimed without evidence that the proposed outfit was being set up to counter the ESN.
IPOB alleged that the motive for the proposed outfit was anti-Igbo.
But the group did provide any evidence as to how the outfit would undermine the ESN.
The statement reads in part: “We know that they intend to counter the formidable ESN, which is protecting and defending Biafrans against terrorists and invaders responsible for the senseless attacks, raping and wanton killings of our mothers, wives and sisters in our farmlands and forests.
“We warn these governors in our region not to heed the mischievous advice and attempt to compromise the security of Biafrans.
“Any group under any nomenclature formed by Dave Umahi and his fellow governors as well as Ohanaeze will be resisted by the people of Old Eastern Region.
“We, therefore, advise every Biafran father and mother to caution their children against joining Umahi’s vigilante group as such an outfit is already the enemy of the people. Their agenda is sinister and anti-Biafra.
“Remember that the real masterminds of the plot…are now set to control Biafraland but ESN and IPOB have remained their only nightmare.
“We are happy to aver that the grand conspiracy by our oppressors to take over the South with the help of compromised leaders is dead on arrival!
“We declare without equivocation that any other group parading as Southeast and Southsouth security outfit will not be allowed to operate on Biafra soil.
“Our people have already launched their defence line – ESN – as our self-acclaimed leaders were nowhere to be found when it counted most.
“Anyone who enlists in any treacherous security outfit sponsored to destabilise our territory will regret such a decision.
“Our message is simply this: IPOB will not allow terrorists any breeding ground on Biafra forests and farmlands.
“The raping, killings and unprovoked attacks by these vampires must stop throughout Biafra territory.
“Anyone against this irreversible resolve of the people to defend themselves against foreign occupation will be crushed!
“ESN has been launched with the mandate of securing Biafraland, and no force can disband this great movement until it’s done with its mandate!”