A mortar fired by Palestinian gunmen in Gaza early Monday morning landed in Israel's western Negev region.
The shell landed in an open area in close proximity to a community, but no injuries or damage were reported.
The incident was the first breach of the ceasefire agreement reached between Israel and armed Palestinian groups in the Strip, which went into effect Thursday morning.
According to the Egyptian-mediated deal, after a few days of calm Israel is supposed to begin easing restrictions and allow the transfer of large amounts of food, gas, construction materials and other goods into Gaza through the Karni and Sufa crossings.
Residents of the western Negev were skeptical of the ceasefire's chances to succeed. "We are familiar with these ceasefires; the fear (of rocket and mortar fire) still exists," Aryeh Cohen of Sderot told Ynet.
"We sense that the truce was declared more for the benefit of the politicians than for the Negev residents."
On Sunday, Sderot residents awoke to the sounds of the Color Red alert system that ended up being a false alarm. Police thought at first that the system identified a Qassam rocket launched towards the city. The night before, the system mistakenly identified a launch from the Kibbutz Be’eri area.