Israel has suspended its participation in the Egyptian-mediated truce talks with Hamas, Israeli media reported Tuesday, quoting an Israeli official who said it was "time for action, not talks."
Earlier Tuesday, the United Nations said it was working with Egypt to broker an end to the latest round of violence between Palestinian terrorists in the Gaza Strip and Israel.
The office of U.N. Middle East envoy Nickolay Mladenov said Monday that efforts were underway "to ensure that Gaza steps back from the brink."
It called for an end to rocket fire and restraint "by all."
Hamas and Islamic Jihad claimed joint responsibility for a barrage of rockets and mortar shells fired at southern Israel over Monday night, as the Israel Defense Forces responded with a wave of more than 100 airstrikes.
The violence was triggered by a botched Israeli military mission in Gaza on Sunday in which seven Palestinian terrorists and a senior IDF officer were killed.
The ensuing barrage of projectiles fired from Gaza into Israel killed one person in Ashkelon and wounded at least 55 others. A 19-year-old soldier was critically wounded when a mortar shell hit a bus.
Egyptian officials warned Israel on Monday that it needed to prevent an escalation in Gaza, Egyptian state TV quoted sources as saying.
The sources said Egypt told Israel of the need to commit to the de-escalation process, and also stepped up efforts with the Palestinians in that regard. But those officials said that all requests for Israeli forces to hold their fire have been rejected.
Israeli officials said that following Monday's attacks, Israel would suspend cease-fire negotiations, vowing to deal Hamas a serious blow.
U.N. Secretary General Antonio Guterres on Monday called for calm and for restraint, a U.N. spokesman said.
"He urges all parties to exercise maximum restraint," Farhan Haq, deputy spokesman for Guterres, said in a statement.
"United Nations Special Coordinator Nickolay Mladenov is working closely with Egypt and all concerned parties to restore calm."

Also on Monday, U.S. special envoy to the Middle East Jason Greenblatt strongly condemned the Hamas leadership in Gaza over the recent escalation.
"Terrorists in Gaza are again attacking Israel with tools of war," Greenblatt tweeted.
"These rocket and mortar attacks on Israeli towns must be condemned by all. Israel is forced once again into military action to defend its citizens. We stand with Israel as it defends itself against these attacks.
"Hamas' activities continue to prove they don't really care about the Palestinians of Gaza and their only interest is to use them for political purposes. Even Palestinian lives seem not to matter to Hamas.
"The world has grown tired of Hamas' violence and the violence of other bad actors in Gaza. This violence prevents any real help for the people of Gaza," Greenblatt said.
France's Foreign Ministry also condemned the indiscriminate rocket fire from the Hamas-ruled Gaza Strip.
"France utterly condemns the large number of rockets intentionally fired in recent hours from the Gaza Strip toward communities in southern Israel, for which Hamas has taken responsibility," the ministry said in a statement.
"France expresses solidarity with the populations who were affected and in particular the families of the victims.
"France asks for the immediate cessation of these activities that are unacceptable and unjustified and calls on all sides to avoid a new cycle of violence in which the civilian population is the first to suffer.
"Our diplomatic representatives are following the situation carefully and are prepared to provide help to any of our countrymen who might need assistance."
EU Ambassador to Israel Emanuele Giaufret tweeted that he was "following with great concern the situation and the indiscriminate firing of rockets toward the south of Israel. Attacks on civilians are unacceptable and need to stop. Everyone must step back from the brink."
The World Jewish Congress also posted on Twitter, saying, "We stand with our brothers and sisters in Israel. We call on the international community to condemn these attacks and to urge Hamas to halt hostilities before more lives are claimed. These acts of terror must stop."
In a statement, WJC President Ron Lauder said, "In the last few hours, Hamas terrorists have fired hundreds of rockets at southern Israel, in a deliberate attempt to terrify residents and inflict maximum damage. These cowardly acts of terror must stop immediately. We call on the international community to unilaterally condemn these attacks and to urge Hamas to halt these hostilities before more lives are claimed."
He said the organization "sends its deep condolences to the family of the IDF officer killed in these clashes, and wishes a full recovery to those wounded. We stand in solidarity with all Israelis at this difficult time."