VELLORE: Three labourers were killed and 11 injured when the roof of a church under construction collapsed in Tamil Nadu's Vellore district on Thursday, an official said.

The 11 injured labourers were rushed in ambulances to the Vellore Government Medical College Hospital, the Christian Medical College Hospital and a hospital in Chittoor in neighbouring Andhra Pradesh.

A police officer said the roof slab of the under-construction Church of South India edifice at Mandi Krishnapuram, near Katpadi, collapsed while labourers were pouring concrete for the roof.

"The 20-foot steel scaffolding and support framework structure collapsed all of a sudden, trapping the workers under heavy concrete debris and rubble," the officer said, confirming the deaths of three labourers.

A team from the National Disaster Response Force (NDRF), Arakkonam, joined the district administration, police and fire service personnel in rescuing the trapped workers at the construction site.

Vellore District Collector PS Leela Alex, who was coordinating the rescue operation at the site on Thursday evening, told reporters that the condition of at least eight labourers was stable.

To a question, she replied that the administration would form a committee to investigate the exact cause of the structural failure and ascertain if the builder had secured all necessary approvals and building permits for the construction of the church.