Chinsurah/Behrampore, Feb. 17: Three children between four and eight were killed since last night because bombs stored in their houses blew up when they mistook them for balls and handled them.

Six-year-old Tasmina Khatoon and her four-year old sister Nasima were killed on the spot when a bomb hidden under wooden planks on the roof of their house exploded this morning at Chakundi village in Hooghly?s Dankuni area.

Police said the sisters were playing on the roof and they tried to pull out the bomb mistaking it for a ball. It exploded, severing an arm of little Nasima and shattering the panes of the nearby Chakundi High School.

?Rajab Ali, the victims? father, and his brother Sohrab Ali have criminal pasts. Our investigation show Sohrab had hidden the bomb that killed his nieces,? said Supratim Sarkar, the Hooghly police superintendent. Both have been arrested.

Last night, eight-year-old Jewel Sheikh met with the same fate at Bausi village in Murshidabad?s Lalgola area, 250 km from Calcutta. The boy spotted a bomb behind a bundle of jute and mistook it for a ball. As soon as he kicked it, the bomb went off killing him instantly.

?Jewel?s father Nakibuddin is an antisocial and has fled the area after the blast. We have arrested his brother,? a police official said.