South Korea on Sunday issued a special travel advisory on Israel and urged South Korean nationals to leave via a third country, if possible, amid security concerns in the wake of the Hamas militant group's rocket attack, the foreign ministry said.

The militant Hamas, which controls the Gaza Strip in Palestine, launched rocket attacks on central and southern areas of Israel during a major Jewish holiday Saturday and Israel staged retaliatory air strikes against it, leaving hundreds of people killed on both sides.

The advisory calls for Korean citizens to cancel or postpone their trips to Israel and to leave the country if they are already there, unless for urgent matters, according to the ministry.

A special advisory is issued by the government in cases of urgent security risks to travelers and can be maintained for up to 90 days.

The ministry said there has been no reported harm to South Korean nationals in Israel.

A total of 570 South Koreans are estimated to be living or staying in Israel, in addition to some 360 traveling in the country, according to the ministry.

Foreign Minister Park Jin called for securing the safety of South Korean nationals and discussed measures during a meeting with relevant officials earlier Sunday, it said.

Korean Air Co., the country's national flag carrier which runs flights connecting Seoul and Tel Aviv three times a week, cancelled a flight that was scheduled to depart for the Israeli city on Monday.

The company is reviewing whether to operate a flight departing from Ben Gurion International Airport as planned, but at a later time than the normal schedule, to assist people returning to South Korea.

Flight schedules for Wednesday and onward have not been confirmed. (Yonhap)