Varanasi, Oct 26 (IANS): Five persons were killed and more than half-a-dozen injured in an explosion in Varanasi, police said on Wednesday.

"Prima facie, the explosion appears to have been triggered by a fire in a stockpile of illegal firecrackers, ahead of Diwali," senior Superintendent of Police (SSP) Nitin Tiwari said.

Two of the dead were identified as Aamna and Sarfaraz, while others are yet to be identified.

A National Disaster Response Force (NDRF) team was at the spot and a search was on to rescue those feared buried under the debris, an officer said.

The incident took place around midnight on Tuesday in a two-storey building on a deep inside lane near the Pitarkund trisection, here.

Rescue and relief operations were underway and at least two persons were still feared buried under the debris. The condition of one woman rescued is said to be critical.

Senior officials including the divisional commissioner, district magistrate, senior superintendent of police and additional security forces were at the spot, a state Home Department official told IANS.

The house, where the explosion took place, belonged to Mohammed Haneef that is adjacent to a grave yard.

Haneef lived with his sons -- Rasheed, Hameed and Habeed, along with more than 20 tenants. The explosion was so massive that one of roofs was blown away, the police said.