Gaza's sole border crossing with Egypt, the only entry point not controlled by Israel, was hit by an Israeli air strike Tuesday for the third time in 24 hours, an AFP photographer and an NGO said.
The third strike against the Rafah crossing consisted of "four missiles" which targeted the Palestinian side of the crossing, local Egyptian group Sinai for Human Rights reported.
Witnesses had said the second strike hit the no-man's land between the Egyptian and Palestinian gates, damaging the hall on the Palestinian side.
Contacted by AFP, the Israel military said it could "neither confirm or deny" any strike on the crossing "at this point".
Sinai for Human Rights said Tuesday's strikes had prompted the closure of the crossing, but there was no immediate confirmation from either side.
Witnesses said Egyptian employees at the border post had been evacuated while "dozens of Palestinian families" who had tried to enter Gaza were turned back towards the Egyptian town of El Arish.
It was the second day the crossing had been hit since Israel launched a ferocious bombardment of Gaza in response to a shock attack by the territory's Hamas rulers on Saturday that left more than 900 people dead in Israel.
Gaza officials have reported 765 people killed so far.
The first strike on Monday had briefly halted passage through the crossing, a security source and witnesses said.
Palestinian officials at Rafah were told by their Egyptian counterparts "to evacuate the crossing immediately due to threats of strikes," according to Iyad al-Buzum, spokesman for Gaza's interior ministry, led by Hamas.
There has been no comment from the Egyptian authorities.
Israel has announced "a complete siege" of Gaza, cutting off food, water, fuel and electricity supplies to the territory's 2.3 million people.
The United Nations said Tuesday that the siege was "prohibited" under international law and called for the establishment of "a humanitarian corridor".
Jordan's King Abdullah II directed officials Tuesday to "send urgent humanitarian and medical aid to our Palestinian brothers in the Gaza Strip through the Rafah crossing, in full and prior coordination with our Egyptian brothers".
Travel through the Rafah crossing is restricted to humanitarian cases and requires often time-consuming authorisations.
Egypt has jointly blockaded Gaza alongside Israel since 2007.
The first Arab country to make peace with Israel in 1979, Egypt has long played the role of intermediary between Hamas and Israel.
On Tuesday, high-level Egyptian security sources claimed there were attempts to "settle the people of Gaza in the (Egypt's) Sinai Peninsula," state-linked private television Al Qahera News reported.
"Egypt has rejected and will reject this matter, which was also rejected by the Palestinian people," the sources said.
Israel has denied pushing Palestinians towards Egypt.