The ministry added that over 150 Palestinians, including several children, were injured during the Israeli airstrikes.
The ceasefire proposal was reached late Sunday night following a proposal by the UN, Qatar and Egypt which have been holding around-the-clock negotiations between the warring sides.
Israel strongly disputed the claim, with Mr Conricus saying that based on intelligence the deaths of the woman and baby were not due to an Israeli strike.
In the northern Gaza Strip, residents searched for a man and his wife missing among the rubble of an apartment building. "We support Israel 100 per cent in its defense of its citizens", he said. But officials in Prime Minister Benjamin Netanyahu's government spoke of a reciprocal return to quiet.
Netanyahu also ordered reinforcements of ground troops, including "tanks, artillery and infantry forces" along the Israeli land borders with Gaza, stoking fears of a possible ground invasion.
Hamas confirmed Hamed Al Khoudary, a senior official in the organisation, was killed and three others seriously injured, when the auto they were driving in was targeted by the Israelis.
A spokesman for Hamas, the Islamist movement that runs Gaza, said in response to Netanyahu's statement that although the recent flare-up in violence had come to an end, the wider conflict would continue.
Signs of normal life slowly returned to Gaza, with banks opening after three days; schools are to reopen on Tuesday.
At around 11:30 pm local time on Sunday, Haaretz, citing diplomatic sources, reported that the United Nations along with Egypt and Qatar had presented a cease fire proposal to the Israelis. "That, in turn, led to an onslaught of mortar and rocket fire from within Gaza, unraveling the tenuous calm".
"The Israeli occupation has to recognise that the Palestinian resistance will not accept leaving the Palestinians suffering forever".
Hamas threatened a similar escalation if the fighting continued.
Plitnick told hosts Sean Blackmon and Bob Schlehuber that "the irony is that the ceasefire basically restores the status quo". Suddenly this morning we saw the notice and began getting ready to leave for home.
The latest flareup comes ahead of the the long-anticipated unveiling of Trump's peace plan.
Indeed, by the end of the weekend, the number of rockets fired into Israel from Gaza reached 690, according to the IDF.
But just days after expanding the fishing zone to 15 nautical miles, Israel scaled it back down on April 30th, citing alleged rocket fire.
There is a dispute over the cause of the deaths of one of the infants and one of the pregnant women - Gaza health officials say both died in an Israeli airstrike, while the Israeli military says they were killed when a militant rocket misfired on launch.
Gazan authorities reported 16 Palestinians killed, including at least six militants, by Israeli strikes in the fighting that began on Saturday with massive rocket fire from the strip.