Israel says it is considering ground operations in Gaza amid an escalation in violence as Israeli tanks and troops deploy along the border.
The Israeli army says three people in Israel were killed by a Hamas rocket following the bombardment of Gaza by Israeli aircraft, tanks and naval gunboats.
Hamas fired dozens of rockets into southern Israel, killing three people, following reported numerous airstrikes by Israel across the Gaza Strip.
Israeli police said the three died when a Palestinian rocket hit a four-storey building in the town of Kiryat Malachi, some 25 km north of Gaza. They were the first Israeli fatalities of the latest conflict to hit the coastal region.