An Israeli man and eight Palestinians have been killed as Islamic militants in Gaza fired rockets and Israel launched airstrikes in response for a second day on Sunday.

Moshe Agadi died on Sunday morning in the coastal city of Ashkelon after being hit by shrapnel following a missile strike on his house, while three other Israelis have been critically injured, two after a strike on a factory in Ashkelon, and one in Kibbutz Erez.

But Israel has denied responsibility for the deaths of a pregnant Palestinian woman and her year-and-a-half-old niece, suggesting they resulted from a Palestinian rocket falling short.

The IDF’s Arabic-languages spokesman Major Avichai Adraee said on Twitter there were “more and more indications… that put serious doubt on the truth” of Hamas claims that the mother and baby were killed by the IDF.

“According to these indications, the death was caused by terrorist activities by Palestinian militants and not by an Israeli strike,” he said.

Over the past two days militants in Gaza have fired around 430 rockets into Israel, reaching as far as the Negev city of Beersheba. While many have been intercepted by Israel’s Iron Dome anti-missile defence system, others have exploded on Israeli homes.

Israeli schools in the south of the country have been closed today.

Israeli fighters have struck hundreds of targets in Gaza, attacking rocket launchers, tunnel shafts and weapons manufacturing facilities.

Newly re-elected Israeli Benjamin Netanyahu said, "I have directed the Israel Defence Force to continue their massive assault against the terror organisations in the Gaza Strip and I instructed them to boost the forces surrounding the Strip with armored corps, artillery and ground forces.”

Israeli President Reuven Rivlin, sending condolences to the Agadi family, said, "We will continue to stand against this dreadful terror and will respond forcefully and unwaveringly to any attack on the security of our people."

There have been periodic outbreaks of violence over the past year with the last truce between Israel and Hamas brokered by Egypt at the end of March.

Israel has blamed the latest flare-up on Hamas after two Israeli soldiers were wounded by a Palestinian gunman on Friday during regular protests at the Israel-Gaza border. Israeli retaliated with an airstrike that killed two militants.

In a statement, the Board of Deputies of British Jews said, "Our hearts go out to the family of Moshe Agadi and also to a Gazan mother and baby senselessly killed by the terrorists' onslaught."