Israeli warplanes pounded Gaza for a fourth day yesterday, killing four more Palestinians, as a teenager died in a mystery blast, raising the death toll so far to 23.

The Israeli army is prepared to expand its activities, and will continue its activities as long as necessary

The latest strike killed a man in his 60s and his daughter in the Jabaliya refugee camp in the northern Gaza Strip, medics said.

Several hours earlier, a teenager was killed nearby, in what the Palestinians claimed was a drone strike.

But the Israeli military said it had not been operating in the area at the time.

As militants kept up a steady stream of rocket fire on towns and cities in southern Israel, Prime Minister Benjamin Netanyahu warned that the army could expand its operations if rocket fire continued.

“The Israeli army is prepared to expand its activities, and will continue its activities as long as necessary,” he told MPs from his rightwing Likud party, hailing the Jewish state’s “crushing offensive abilities”.

During the day, Israeli warplanes carried out at least nine strikes across the territory, targeting a weapons storage facility and rocket-launching sites, and killing two militants and two civilians.

Both militants, who belonged to Islamic Jihad’s armed wing, the Al-Quds Brigade, were killed in strikes around the southern city of Khan Yunis.

And shortly afterwards, a blast killed a 15-year-old boy and wounded six others in what emergency services spokesman Adham Abu Selmiya said was an Israeli drone strike.

But a military spokesman denied the air force had carried out any attacks in the area at the time, and an AFP correspondent at the scene confirmed there was no sign of an air strike.

The latest attack in Jabaliya killed two civilians, Mohammed Mustafa al-Hasumi, 65, and his 35-year-old daughter Faiza.

In a statement, the Israeli military said the strike targeted “a terrorist squad” who had just launched a rocket towards Israel.

While it acknowledged the strike may have caused “the apparent injury of uninvolved persons,” it said the incident was “a blatant example of how terror organisations use human shields to carry out terror attacks”.