The incident occurred in an illegal cracker manufacturing unit in Parak locality of Mohan village, SP Unnao Sonia Singh told IANS.
The impact of the explosion was so severe that the entire house collapsed. Six people died when they were buried under the rubble.
Four other people injured in the mishap were rushed to the King George's Medical University Trauma Centre here and their condition was stated to be serious.
The bodies have been sent for post-mortem. Police have cleared the area as more explosives may be buried under the debris.
Unnao is about 60 km from state capital Lucknow.
--IANS (Posted on 19-09-2013)