The rocket and one mortar round landed in an open area in the Eshkol region, the Times of Israel reported. Two of the mortar shells failed to cross into Israel, landing in the northern part of the Gaza Strip.
No injuries or damage were reported.
Thursday's attack came one day after Israel bombed sites in the Gaza Strip and militants fired two rockets into Israel. There were several attempted attacks on Israel Tuesday apparently in response to a Palestinian inmate dying of cancer in prison, the newspaper said.
The renewed violence could threaten the unofficial cease-fire established after November's Operation Pillar of Defense.
"The renewed violations of the cease-fire risk undermining the 'understanding' reached between Israel and Gaza on Nov. 21, and unraveling the gradual but tangible improvements achieved since then in the easing of the closure and the security situation in Gaza and southern Israel," United Nations Middle East peace process coordinator Robert Serry said in a statement Wednesday.