Israel pressed its assault against the Hamas-ruled Gaza Strip with a series of strikes on Saturday, killing at least 26 Palestinians, including four children, medical officials said.
The fighting was concentrated in and around the crowded Jabaliya refugee camp in northern Gaza, where Israeli special forces crept in just after midnight followed by a wider incursion involving tanks and helicopters.
Doctor Muawiya Hassanein, head of Gaza emergency medical services, told AFP at least 26 people were killed, most of them by a "great number of rockets fired by Israeli planes" in and around the camp and town of Jabaliya.
Witnesses also reported clashes in the nearby Tufah neighbourhood in northern Gaza City.
The high death toll makes Saturday's operation the deadliest raid on Gaza in several months and comes at the end of a sharp four-day escalation of violence that has killed nearly 60 people.
The dead included at least four children and two women, medics said, including a 12-year-old girl and her 11-year-old brother, who relatives said were killed by shrapnel as they slept inside their home.
At least 10 militants were killed in the operation, including five from the Islamist Hamas movement and another two from Islamic Jihad, as several missiles slammed into the town and fighters exchanged fire with Israeli soldiers.
At least five Israeli soldiers were wounded, the army said.
An Israeli army spokeswoman said troops had killed at least 15 Palestinian militants, "all of them planting explosive devices or shooting."
Gaza militants meanwhile fired at least 30 rockets at southern Israel, army radio reported.
The latest deaths came after tens of thousands of Gazans poured into the streets of the Hamas-run territory on Friday to protest against Israeli raids that killed more than 30 Palestinians. (AFP)
Israeli strikes kill 26 in fierce Gaza incursion