Two Israeli tourists and their Egyptian guide have been shot dead in the Egyptian city of Alexandria, the Israeli foreign ministry says.

Another Israeli was wounded in the attack on Sunday morning, which the ministry said a "local" carried out.

There was no immediate confirmation from Egyptian authorities.

But the private Extra News TV channel reported that a policeman had opened fire on a group visiting an ancient Roman site known as Pompey's Pillar.

The assailant fired "at random" using his personal weapon, it cited a security source as saying, adding that he was detained at the scene.

Footage of the aftermath of the attack posted on social media showed at least two people apparently dead on the ground at an archaeological site.

The Israeli foreign ministry said it was working with Egyptian authorities in order to return the Israeli citizens to Israel as soon as possible.

The shooting happened a day after the Palestinian militant group Hamas launched an unprecedented attack on southern Israel, sending hundreds of gunmen across the frontier from Gaza and launching thousands of rockets.

At least 350 people are reported to have been killed in Israel, while another 313 people in Gaza have been killed in retaliatory Israeli air strikes.

Egypt was the first Arab country to make peace with Israel in 1979, but Israeli policies towards the Palestinians make it unpopular with many Egyptians.

In June, an Egyptian police conscript killed three Israeli soldiers near the two countries' border. Egypt said he exchanged fire with the soldiers while chasing drug smugglers, but Israel said it was a terrorist attack.