New Delhi:Haryana chief minister Manohar Lal Khattar has announced a CBI investigation into the murder of seven-year-old Pradhyumn Thakur inside a Gurgaon branch of Ryan International School on September 8.

The CM made the announcement while meeting Pradhyumn's parents at their home, a week after the boy was murdered in the washroom of the school's Bhondsi campus.

 "It was an extremely unfortunate incident. I have come to meet the family and express my grief," Khattar said at the Thakurs' Shyam Kunj residence. 

Meanwhile, Ryan group founder A F Pinto, his wife Grace and son Ryan moved the Punjab and Haryana high court in Chandigarh for pre-arrest bail. Hearing is likely to take place next week.

A Mumbai court had earlier granted the Pintos interim protection till Friday.

The CM said he was acceding to the family's demand of a CBI inquiry. "Haryana Police has been conducting the probe properly. But we will write to the home ministry demanding a CBI probe. We will also appeal to the CBI to fast-track the case," he said.

Khattar said, "All lapses will be looked into and strict action will be taken against all of those found to be involved in the case."

Ashok Kumar (42), conductor of a school bus at Ryan Bhondsi, was arrested on the September 8 evening. Police say he tried to sexually assault the boy and murdered him with a knife -purportedly from the bus toolkit that he had brought to the toilet to wash -when he resisted. 

Later, police registered another case under Section 75 of the Juvenile Justice Act for security lapses by the school and arrested two senior Ryan officials -its north India head Francis Thomas and HR head Jayesh Thomas. The charges were added to the original FIR registered for murder.