Kolkata, Oct 17 (IANS): A day after West Bengal Chief Minister Mamata Banerjee's seven-day ultimatum to Maoists to choose between guns and negotiation, ultras' posters in Junglemahal Sunday threatened Trinamool Congress leaders if their pre-poll promise of withdrawing joint security forces and releasing jailed extremists was not kept.

The three handwritten red posters, pasted on walls at Bhadutala market of Salboni in West Midnapore district, were in Bengali.

"Keep your poll promise of withdrawing joint forces. Release jailed political prisoners," said one of the posters.

"If the promises are not kept the lives of Trinamool Congress leaders will be under threat," it said.

West Midnapore district administration officials said they were investigating the matter.

"I am giving you seven days' time. Think over this. If you want a peaceful solution to the problem, no issues. We want the doors of negotiations to be open. This is a last chance. Bloodshed and negotiations cannot go together," the chief minister said addressing a largely attended rally at the Jhargram stadium of West Midnapore district Saturday.