Israeli attack helicopters struck a Palestinian police post in northern Gaza after mortars were fired at Jewish settlements.
One person was slightly injured in the Israeli strike, Palestinian witnesses said. The building had been evacuated before the attack.
The Israeli military claimed the air strike was retaliation for Palestinian mortar fire at Jewish settlements in Gaza.
An Israeli girl was slightly wounded by a mortar shell, a military statement said, "despite Israeli demands that the mortar attacks cease".
Palestinian security chief Maj Gen Abdel Razek Majaidie said the helicopters fired four missiles at the installation, belonging to an elite unit of the Palestinian police.
He said two surface-to-surface missiles also hit the building, causing considerable damage.
In Ramallah, Nabil Abu Rdeneh, an aide to Mr Yasser Arafat, said the Israeli attacks in Gaza and Hebron were a "severe violation" of agreements and a "dangerous escalation aimed at sabotaging the mission" of US peace envoy Mr Anthony Zinni.
AP