Israeli warplanes struck four new Hamas positions in the southern Gaza Strip on Thursday, as a flare-up continued to threaten a 2014 ceasefire agreement.

"In response to the ongoing attacks against Israeli forces, IAF aircraft targeted four Hamas military posts in the southern Gaza Strip," an army statement said, referring to the blockaded Palestinian enclave.

There were no immediate reports of casualties during the raids, which Palestinian security sources said landed in farmlands near the border.