Police say a building that was under construction collapsed and killed 12 people, including two children, in the north Indian state of Uttar Pradesh.

The victims were sleeping on the ground floor when the partially built first floor fell on top of them.

Police Superintendent Chandauli Muniraj says two people were being treated in a hospital, but three people escaped unhurt.

The building's owner Mohammad Kamarrudin was among the 12 people killed, along with two children under 8 years old.

It was not immediately clear what caused the structure to collapse in the city of Mughalsarai, southeast of state capital Lucknow.

Building collapses are common in India, where high housing demand and lax regulations have encouraged some builders to cut corners or use substandard materials.