A portion of a government school building in Krishnagiri district collapsed during school hours today in heavy rains, but the 81 primary children were away attending morning assembly at the time.

The Government Middle School at Natanamkottai village in the district, constructed in 1963, has 203 students. The 81 students, from first to fourth standard were taking part in the morning prayer when part of the building collapsed

Anxious parents, who rushed to the school on hearing about the news, alleged that the 'lethargy' of the education department and the administration was responsible for the accident.

Though a decision was taken last year to renovate the school, work had been delayed for various reasons, they said. The parents warned that they would stage an agitation if the government failed to renovate the school in 15 days.