Six people, including two Hamas fighters, were killed Friday in separate Gaza City explosions, Shiva Hospital spokesman said.
A Hamas member of parliament escaped injury in a third blast, Hamas said.
The Islamist group Hamas blamed the attacks on members of Palestinian Authority President Mahmoud Abbas' Fatah party. There was no immediate comment from Fatah.
The two factions have been bitterly divided since Hamas drove Abbas' security forces from Gaza last year.
Five of the deaths resulted from an explosion Friday night behind a tent on the beach, the hospital spokesman said. Among the dead were two members of Hamas and a girl 5 to 7 years old, he said. The identities of the other two fatalities were undetermined.
He said 20 people were wounded in that blast, which occurred about 9:30 p.m. (2:30 p.m. ET).
Earlier in the day, one man died and two people were wounded when a bomb exploded at a coffee shop.
The Hamas politician escaped injury from an explosion Friday morning outside his home.