Hamas has committed “cold-blooded murder of innocent men, women, and children,” Israeli President Isaac Herzog said in an address to the nation after militants launched an unprecedented surprise multi-front attack.

The centre and south of Israel sustained rocket fire for more than three and a half hours as Hamas fighters simultaneously infiltrated as many as 14 Israeli towns, killing and capturing Israeli soldiers and civilians.

At least 40 people are confirmed dead and a further 740 wounded.

Benjamin Netanyahu, the Israeli Prime Minister declared war and his forces have begun striking the densely populated Gaza Strip.

Thousands of reservists are reported to have been called up.

The US has promised it will work to ensure Israel has “what it needs to defend itself” in the coming days.