At least seven security personnel, including six Central Reserved Police Force jawans, were killed in a landmine blast triggered by maoist ultras in Jharkhand's West Singhbhum district on Thursday.

Inspector General of Police (operations) B C Verma told UNI in Ranchi that proscribed CPI (Maoist) ultras triggered the blast between Thalkobad and Karmpada villages under Kiriburu police station when the securitymen were returning from Thalkobad in a hired minibus after diffusing a landmine in a school.

The driver of the vehicle, a Jharkhand police jawan, was also killed in the incident.

Verma said an intense combing operation was being conducted in the area to nab the ultras.