Israel was warned of a potential violent attack days before the Hamas militant group launched a barrage of rockets into the country, a US congressional panel chair said.
Egypt had warned Israelis "that an event like this could happen" at least "three days" before the Hamas attack last weekend, House Foreign Affairs chair Michael McCaul told reporters on Wednesday following a closed-door intelligence briefing on the crisis.
"I don't want to get too much into classified, but a warning was given," the Republican member of Congress said, according to AFP. "I think the question was at what level."
Israel denied the reports of Egypt sending a warning as "absolutely false".
"No message in advance has arrived from Egypt and the prime minister has neither spoken, nor met, with the head of Egyptian intelligence since the formation of the government, neither directly nor indirectly," prime minister Benjamin Netanyahu's office said in a tweet.
Hamas’s ability to launch a complex assault from the heavily surveilled Gaza Strip appeared to be an unprecedented intelligence failure by Israel and its ally, the US, according to experts.
An Egyptian intelligence official earlier this week claimed that Cairo had repeatedly warned Israel that "something big" was being planned from Gaza.
"We have warned them an explosion of the situation is coming, and very soon, and it would be big," an unnamed Egyptian official was quoted by the Associated Press as saying.
The official said Israel "underestimated such warnings" from Gaza and focused on the occupied West Bank.
Israeli jets have pounded Gaza City for days in retaliation against the weekend attack by Hamas militants who rampaged through towns and villages, killing 1,200 people and taking scores of hostages, including foreign nationals.
The death toll in Gaza has risen to 1,200, with some 340,000 of Gaza’s 2.3 million population displaced due to the war.
"We are not quite sure how we missed it," Mr McCaul said, adding the attack may have been planned as long as a year ago.
Meanwhile, hundreds of thousands of Israeli troops gathered in multiple divisions on the border of the enclave as the Israel Defence Forces (IDF) prepared for a ground invasion of Gaza.
Mr Netanyahu on Wednesday vowed to “crush and destroy” Hamas. “Every Hamas member is a dead man,” he said in a televised address.
