Investigators are trying to prepare a sketch of the suspect in connection with the rape of a seven-year-old girl in a municipal school last Thursday, police sources said.

Police, which have questioned over a dozen people today, are also trying to ascertain who all entered the school in Mangolpuri on the day of the incident after lunch hours, they said.

Sources said they were preparing a sketch of the suspect with the help of the victim.

"The victim had told police that the offender was not a person whom she knows," a senior police official said.

No arrest has been made so far in the case.

The Class II student was raped by an unidentified man inside the North Delhi Municipal Corporation-run primary school in Mangolpuri L Block of north-west Delhi on Thursday.

North Delhi Municipal Corporation Commissioner P K Gupta had yesterday suspended five staff of the school. The suspended officials were school inspector Balraj Singh, principal Neelam Karwal, class teacher Monica Kohli, school attendant Sushila and guard Kailash.

Gupta also constituted a five-member committee to inquire and fix the responsibility in the sexual assault case.