Police started a case under sections of the Protection of Children from Sexual Offences Act (Pocso) against “unknown labourers” on Friday after some parents protested outside an all-girls school in north Calcutta on Thursday against allegations of the harassment of a Class II student by a mason working on the school premises.

Police sources said 11 labourers were engaged by the school for a plaster and paint job and of them, three had fled. The remaining eight have been detained for questioning.

No one was arrested till late on Friday.

The plaster and paint work on the premises has been stopped.

The school management, including the secretary, headmistress and other officials, met parents on Friday.

One of the demands of the parents was to stop the work on the premises during school hours. “They have asked for more help (ayahs), and we will have two more from Monday. They want more CCTV cameras and we are looking into it,” said the school secretary.

Classes were suspended on Friday following the protests on the previous day. “We will resume classes on Monday,” the headmistress said.

A school official said the school had not ignored the complaint of the girl. “It has been alleged that a mason had offered candy to the child. We heard that the girl reported the matter to her mother on Tuesday. The headmistress came to know about the allegation from another parent on Wednesday and called the child to find out what happened,” the official said.