At least four people were wounded by Israel's airstrikes, which targeted several militant sites across the Gaza Strip, officials said.
"Three bombs were dropped by the air force on a Hamas military base east of Nusseirat refugee camp," south of Gaza city, a Palestinian security source said, in reference to the Islamist movement that runs the Gaza strip.
The planes also made two raids against Hamas lookout posts along the border with Israel, east of Khan Yunis, and on a base of Islamic Jihad's military wing in the north of the strip, the source said.
Hamas security forces blocked journalists from approaching one of the targets in Rafah, suggesting a sensitive installation had been hit, The Associated Press reported.
Dawn rocket attack
The ariel bombardment followed a rocket attack launched from Palestinian territory into southern Israel earlier on Monday, which the Israeli military said caused no casualties.
There was no immediate claim of responsibility for the rocket fire, which landed in an empty field. But Israel has warned that Hamas bears overall responsibility for what happens in the Gaza Strip.
Hamas spokesman Fawzi Barhoum described Israel's action as "unacceptable," accusing the Jewish state of a "continuation of this dangerous escalation against Gaza."
Since a 50-day war between Israel and Gaza militants in the summer of 2014, a cease-fire has largely held. But militants in Gaza occasionally fire rockets at Israel's south.
Earlier this month, Israel hit Gaza with tank fire and air strikes in response to a projectile fired from the Palestinian territory. The Israeli attack wounded three Palestinians.
Israel has vowed a harsher response to Hamas' "provocation" in future.
mm/jm (AFP, AP, Reuters)