Witnesses say Israeli warplanes have struck the Palestinian Interior Ministry for the second time in less than a week, causing damage and wounding at least three people.
The Israeli military confirmed the airstrike in Gaza City early Wednesday.
Hours earlier, a Palestinian rocket landed in the center of Israel's southern coastal city of Ashkelon for the first time. There were no casualties.
The armed wing of Hamas claimed responsibility for the attack.
Israeli Prime Minister Ehud Olmert called the rocket attack a major escalation in Palestinian terror against the Jewish state. He said there will be major consequences and warned Hamas will be the first to feel them.
And Israeli Defense Minister Amir Peretz ordered Israeli forces to increase the pace of their operation in the Gaza Strip aimed at freeing an Israeli soldier.
Militants from the armed wing of Hamas and two other groups kidnapped the Israeli soldier June 25.
Witnesses say Israeli aircraft also attacked a Hamas training camp in the Gaza Strip early today. No casualties were reported.
Separately, U.N. aid agencies say the recent easing of the total blockage of the Gaza Strip by Israeli forces has averted a humanitarian catastrophe for now. A spokesman for the U.N. Relief and Works Agency, Matthias Burchard, says fuel and basic foodstuffs are getting through but there is a huge backlog.
Some information for this report provided by AP and Reuters.