Bangalore, Aug 5 (IANS): Three people were killed and six others injured Monday when the roof of a wedding hall under construction collapsed in Bangalore's Kengari satellite town, a fire brigade official said.

"The mishap took place when the roof of the second floor of the building crashed trapping about 20-25 workers under heavy concrete material. Three persons died and six others were critically injured while we have rescued 10 people so far," regional fire officer M. Ramaswamy told IANS here.

The injured were taken from Kengari, about 20 km from here, to a state-run hospital.

"The rescue operation is on to find if more workers are still trapped under the debris as the supporting walls also collapsed under the impact of the crash," Ramaswamy said.

A religious institution was building a three-floor wedding hall at the site, where work was hampered due to heavy rain in the last two days.

"Police have registered a case against the building contractor and are investigating to ascertain if any spurious material was used for construction," Ramaswamy said.

Home Minister K.J. George and officials visited the incident site.