In a major blow to the Gorkha Janmukti Morcha (GJM), a city court on Saturday issued arrest warrants against its entire top leadership, including supremo Bimal Gurung, in a murder case.The case was related to the murder of All India Gorkha League president Madan Tamang, who was stabbed to death in Darjeeling on May 21, 2010.The CBI, which is probing the case, on May 29, 2015, submitted a charge sheet indicting 23 people, including Gurung, of various offences including murder and criminal conspiracy.Gurung is also the chief of the autonomous hill council Gorkhaland Territorial Administration.