The Trinamool Congress (TMC) will observe "black day" throughout West Bengal on August 4 and 5 to protest against the detention and "manhandling" of its leaders at the Silchar airport in Assam yesterday, a senior party leader said today.

TMC secretary general and West Bengal Education Minister Partha Chatterjee said the party will observe "black day" in every block and district of the state on Saturday and Sunday. "We condemn the way the public representatives were manhandled and detained by the Assam police at the Silchar airport. They being MPs had every right to visit a place, but all rules were violated and our party delegation was stopped. This is shameful," he told reporters here.