Gaza terrorists shot a rocket and three mortar shells at Israel early Thursday morning, marking a third straight day of projectile fire after several months of calm.

Initial reports indicated that the rocket landed in an open area in the Eshkol region, as did one of the mortar rounds. Two of the shells fired failed to cross the fence into Israel and landed in the northern part of the Gaza Strip. There were no reports of injuries or damage.

On Wednesday morning, two rockets were fired into Israel, hours after Israel bombed sites in the Gaza Strip in response to several attempted attacks on Tuesday.

The airstrike was the first since November’s Operation Pillar of Defense, launched by the Israel Defense Forces to stem missile fire from the Strip.

Officials have expressed fears that the renewed tensions between Israel and Gaza could spell the end of the informal cease-fire and spiral into renewed cross-border volleys that were a frequent occurrence leading up to November’s eight-day mini war.

“The renewed violations of the ceasefire risk undermining the ‘understanding’ reached between Israel and Gaza on November 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.

The rocket fire on Tuesday, which sparked the latest round of violence, was seemingly launched in response to the death of a Palestinian prisoner of cancer.

On Wednesday evening, Prime Minister Benjamin Netanyahu promised “vigorous” blowback if fire emanating from the Hamas-controlled enclave does not cease.

Hamas, for its part, has reportedly been trying curb the rocket fire from the territory, and has even sent calming messages to Israel to the effect that it is working to uphold the ceasefire by, among other measures, arresting members of factions that have been shooting rockets, Israel’s Channel 2 news said Wednesday.