Unknown assailants attacked a residential school at Kanjiramkulam near Thiruvananthapuram, setting the school bus on fire and damaging seven other buses parked on the premises.

It was on Tuesday morning that authorities of Mount Carmel Residential School, Kanjiramkulam, got to know of the attack which was carried out reportedly at night.

Forensic and fingerprint experts will visit the site soon to collect evidence. A team from Kanjiramkulam police is camping at the school. Authorities have declared a holiday for the school in the wake of the attack.

Police are trying to examine the CCTV visuals to get a clue about the attackers. It is to be noted that the attack happened in a school where security guards are deployed round the clock.