Wall Street’s biggest banks have told staff in Israel to work from home after an unprecedented invasion of the country by Hamas militants set off a war.

JPMorgan Chase & Co. which has about 200 employees in Israel, and Morgan Stanley have asked their workers not to come to the office, people familiar with the plans said. Goldman Sachs Group Inc. and Bank of America Corp. also asked staff to stay home. Bank of America closed its office in Tel Aviv as it continues to monitor the situation, it said in a memo to staff.

“We remain in close, ongoing touch with our team in Israel,” Bank of America’s president of international, Bernie Mensah, said in the memo. “They are safe, and we are ensuring they have support and resources as needed.”

A spokesman for Goldman confirmed its decision, while representatives for JPMorgan and Morgan Stanley declined to comment. A spokesman for Bank of America confirmed the contents of the memo.

At Citigroup Inc., staff in Israel can work from home or in the office. “We are monitoring the situation in Israel carefully,” a spokeswoman for the bank said. “The safety of our colleagues is our highest priority and at the same time we remain focused on serving our clients.”

Israel Latest: Army Stops Lebanon Incursion, Calls Up 300,000

The attack by the Gaza-based militant group Hamas, which started Saturday, has killed more than 700 Israelis, mostly civilians. Some 500 Palestinians have been killed in retaliatory strikes, Palestinian authorities said.

Israel’s military said it killed a number of infiltrators who crossed into its territory from Lebanon as it tackles threats on multiple fronts and announced its largest ever mobilization.

(Updates with details on Bank of America in second paragraph.)