Last Updated Jul 15, 2014 1:10 PM EDT
GAZA CITY, Gaza Strip -- An Egyptian truce proposal for the conflict in Gaza quickly unraveled Tuesday, after the Islamic militant Hamas rejected the plan, Gaza militants fired scores of rockets at Israel and Israel responded with more than a dozen air strikes.
Israeli police said a man in his 30s was killed by fire from the Gaza Strip, the first Israeli death in more than a week of fighting.
The speedy resumption of violence, less than a day after Egypt presented its cease-fire plan, illustrated that it will be harder this time than in the past to negotiate an end to Israel-Hamas fighting.
A key difference to a previous truce in 2012 is that Hamas does not trust the current rulers of Egypt who deposed a Hamas-friendly government in Cairo a year ago.
Israel had agreed to the Egyptian plan, proposed late Monday. Under it, a 12-hour period of de-escalation was to begin at mid-morning Tuesday. Once both sides agree to halt hostilities, they would negotiate the terms of a longer-term truce.
Gaza militants responded by firing dozens of rockets after the proposed start of the de-escalation, some of them reaching deep into Israel, though not causing injuries. CBS News' Michal Ben-Gal reported there was a heavy barrage of rockets towards Tel-Aviv and central Israel on Tuesday evening.
Israel, which had warned it would strike Gaza harder than before if Hamas did not halt hostilities, held its fire for several hours, but resumed air strikes by mid-afternoon Tuesday.
After the renewed rocket fire from Gaza on Tuesday, Israeli Prime Minister Benjamin Netanyahu and Defense Minister Moshe Yaalon "directed the military to act with intensity against terror targets in Gaza," said an Israeli official who spoke on condition of anonymity because he was not authorized to discuss the decision with the media.
Since the outbreak of cross-border fighting on July 8, more than 190 Palestinians have been killed in hundreds of Israeli air strikes and millions of Israelis have been exposed to rocket fire. The current round of violence was the third in just over five years. The previous one, in 2012, eventually ended with the help of Egypt, at the time seen as a trusted broker by Hamas.
But Hamas distrusts Egypt's current rulers, who have tightened the border blockade on Gaza, including curtailing travel in and out of the territory. An easing of the blockade of the coastal strip is key to the survival of Hamas.
Hamas officials on Tuesday rejected the Egyptian plan as is, noting they weren't consulted by Cairo. Some portrayed the truce offer as an ultimatum presented to Hamas by Israel and Egypt.
Earlier, a statement from Hamas' military wing, the al-Qassam Brigades, said it hadn't even been presented with the Egyptian proposal but that, "it is not worth the ink that wrote it."
Hamas officials, including Osama Hamdan, a senior aide to top leader Khaled Mashaal, said the Egyptian plan offered no tangible achievements, particularly on easing a border blockade of the coastal strip, which has been enforced by Israel and Egypt for the past seven years.
Hamdan said the movement needs detailed assurances that Gaza's borders will be opened, particularly the Rafah crossing between Gaza and Egypt, the territory's main gate to the world.
Hamas also wants to be recognized by Egypt as a partner in any truce efforts. "We did not receive any official draft of this Egyptian proposal," said Sami Abu Zuhri, a senior Hamas official in Gaza. He said the Egyptian plan, as is, is "not acceptable."
Hamas officials are weary of promises by Egypt and Israel to ease the border blockade. Such promises were also part of a truce in 2012, but were not fully implemented as the strip remained under blockade.
Before the outbreak of the latest round of fighting, the militant group found itself in a serious financial crisis because the Egyptian closure had prevented cash and goods from coming into the strip through hundreds of smuggling tunnels under the Gaza-Egypt border.
In response to the Egyptian truce plan, Gaza militants fired some 50 rockets at Israel on Tuesday,
The Israeli military said several rockets reached deep into Israel, including near the northern port city of Haifa. Sirens also went off in the towns of Hadera and Zichron Yaakov, more than 100 kilometers (60 miles) north of Gaza.
The military wing of Hamas, which has been responsible for most of the hundreds of rockets launched at Israel in the past week, said the Egyptian plan "wasn't worth the ink it was written with."
As fighting resumed, the Israeli military faced difficult choices. It has warned in the past that it might launch a ground of offensive in Gaza and has amassed thousands of troops on Gaza's border.
However, entering Gaza would likely drive up casualties on both sides. In the past, Israel has shied away from ground operations for fear of getting entangled in the densely populated territory of 1.7 million.
In Vienna, Secretary of State John Kerry blasted Hamas for firing rockets after the proposed cease-fire was to have taken effect.
"I cannot condemn strongly enough the actions of Hamas," Kerry told reporters. In contrast, he praised Egypt's intervention and Israel's acceptance of the deal.
Kerry said the U.S. would continue pushing for a cease-fire is because of the potential for the violence escalating even further.