Israeli Defence Minister Yoav Gallant has announced a "complete" blockade of Gaza, including a ban on food, electricity, water and fuel, after a surprise attack by Hamas militants on Israel.
"We are putting a complete siege on Gaza … No electricity, no food, no water, no gas – it’s all closed,” Gallant said in a video statement.
Israel's troops were still battling on Monday to clear out Hamas gunmen more than two days after they burst across the fence from Gaza.
Meanwhile, several international air carriers have suspended or reined in flight services to or from Tel Aviv, saying they were waiting for safety conditions to improve.
Regulators including the United States' Federal Aviation Administration, the European Union Aviation Safety Agency and Israel's aviation authority urged airlines to use caution in the region's airspace, but stopped short of suspending flights.
Israel's civil aviation authority asked airlines to "review current security and threat information" amid the conflict, and changed some air traffic routes. It noted that delays were expected and advised airlines to carry extra fuel.
On Sunday, US air carriers United Airlines, Delta Air Lines and American Airlines suspended direct flights following the FAA's caution advisories.
The US airlines normally run direct services from major cities such as New York, Chicago, Washington, DC and Miami.
United said it had run two scheduled flights to the United States from Israel late on Saturday and early on Sunday but then suspended services. Delta representatives said flights this week were cancelled and the situation was being monitored.