A road in a residential neighbourhood of the southern town of Sderot was slightly damaged, Israeli police said.
Gaza security sources said Israeli aircraft retaliated with strikes on open ground near the Nuseirat refugee camp in the central Gaza Strip and against a base of the Hamas military wing in the city of Khan Yunis further south.
Israel holds Gaza's Hamas rulers responsible for all rocket fire from the territory regardless of who launches it.
The Israeli navy also fired at the Khan Yunis base, the sources said, adding that altogether two people were wounded.
More From This Section
It made no mention of naval action.
"We shall continue to act forcefully against our enemies," Prime Minister Benjamin Netanyahu wrote on his official Twitter account.
"Today, the Israel Defence Forces attacked in the Gaza Strip those who sought to harm the citizens of Israel and disturb the calm of the holiday."
The attacks came during a public holiday in Israel marking the last day of the Jewish festival of Passover.
An Israeli army statement said that prior to the rocket barrage, militants fired an anti-tank missile at an army patrol on the border fence but caused no casualties.