Imphal: Four National People's Party (NPP) ministers including Deputy Chief Minister Y JoyKumar Singh resigned from the BJP-led government in Manipur on Wednesday.The other three who tendered their resignation letters are Tribal and Hills Area Development Minister N Kayishii, Youth Affairs and Sports Minister Letpao Haokip and Health and Family Welfare Minister L Jayanta Kumar Singh.Joykumar Singh also held the finance portfolio.In separate letters addressed to Chief Minister N Biren Singh, Joykumar, Haokip and Kayishii stated, "I am to intimate that I tender my resignation from Cabinet ministership of the BJP-led coalition government of Manipur led by your good self."Meanwhile, speaking to reporters, Joykumar Singh said, "We have submitted.