Srinagar, Oct 10 (IANS): The National Investigation Agency (NIA) has summoned 40 teachers on Sunday in connection with civilian target killings here, the investigation of which the agency has formally taken over from the local police.

Top officials of the IB, including Tapan Deka, the head of counter terrorism wing in the agency are camping in Srinagar under the directions of the Union Home Minister Amit Shah, who has taken a serious note of the civilian killings by the terrorists.

"The home minister has made it clear to the Lt. Governor Manoj Sinha that unless the terrorists involved in these killings are quickly brought to justice, many heads will roll in the UT", top sources told IANS.

The J&K Police have already detained over 400 people in connection with the FIRs lodged in different police stations pertaining to the civilian killings in the Valley.

Top sources said the detained people have known links with the proscribed Jamaat-e-Islami, Tehreek-e-Hurriyat and others with known terror links in the past.

The NIA has taken over the investigation into the murders of principal Supinder Kour and teacher Deepak Chand, who were killed by terrorists inside the school premises in the Eidgah area of Srinagar city.

The 40 teachers summoned by the NIA at 4 p.m. on Sunday at its Church Lane office in Srinagar belong to various schools in Srinagar city.