The Israeli army said two rockets were fired from Gaza towards Israel on Thursday night without causing any casualties or damage, and that one had been intercepted by air defences.

"Two rockets were just fired at Israel from Gaza. The IDF's Aerial Defence Systems (Iron Dome) intercepted one of the rockets," the army said on Twitter.

There was no immediate claim of responsibility for the rockets but sirens sounded in a region of southern Israel that borders the Gaza Strip to warn residents of the incoming fire.

The last reported rocket attack from Gaza was on Tuesday night.

It came after the army announced it had found a new tunnel that crosses "dozens of metres (yards) into Israel" from the Israeli-blockaded Palestinian coastal enclave.

The next day the army said the tunnel belonged to the Islamist movement Hamas which controls Gaza.

Authorities have discovered some 20 tunnels originating from Gaza since 2014, army spokesman Jonathan Conricus said this week.

Israel has fought three wars with Hamas since the Islamists seized Gaza in 2007 and there have been numerous flare-ups.