The 11 policemen and Deputy Superintendent of Police Anup Badaik were in two vehicles when the Maoists triggered the blast in Maneka police station area close to Palamau district, Latehar Superintendent of Police Michael S Raj told PTI.
The policemen in the vehicles engaged the Maoists for some time, after which they were joined by 60 to 70 CRPF personnel, following which the ultras fled, Raj said.
The Maoists had killed Pakur Superintendent of Police Amarjit Balihar in July this year.