Left parties today approached the Election Commission demanding that West Bengal's borders with other states be sealed during the coming Assembly polls there to ensure that Maoists do not trigger violence. A six-member delegation led by CPM leader Sitaram Yechury met the Election Commissioners and apprised them of their apprehension about Maoists' plan. Speaking to reporters later, Mr. Yechury said given the terrain on the bordering states like Jharkhand, Odisha and Bihar, it is imperative that the borders are sealed.