South Korea's Foreign Ministry has imposed a travel ban on the Israel-Lebanon border region and issued a special travel advisory for Iran, effective from Wednesday, as tensions rise in the Middle East following the assassination of Hamas political leader Ismail Haniyeh in Tehran last week.

The areas subject to the travel ban, which is the highest level in the four-tier travel advisory system, include the northern border region of Israel within 4 km of the Blue Line and the southern border region of Lebanon within 5 km of the Blue Line.

The Blue Line is a demarcation line, not an official international border, established by the United Nations in 2000 to verify Israel's military withdrawal from southern Lebanon.

"We urge citizens who plan to travel to the Israel-Lebanon border region, now designated as a travel ban area, to cancel their plans. We also request that any citizens currently in the region evacuate immediately," the Foreign Ministry said in a statement.

"We once again strongly recommend our citizens residing in Lebanon and Israel leave as soon as possible using currently available flights," the ministry echoed its warning earlier this week.

The level 3 alert, which advises nationals to leave the designated areas unless in an emergency and to postpone or cancel planned trips to these regions, remains in effect for all other areas of Israel and Lebanon. This excludes the Gaza Strip, which is under a travel ban, and the Israel-Lebanon border region.

For Iran, the existing level 3 travel advisory for certain regions remains in effect, while other regions previously under level 2 alert, which advises exercising caution, have been elevated to a special travel advisory.

"We advise our citizens planning to visit Iran, which is under a special travel advisory, to cancel or postpone their trips. For those currently in the area, please leave for a safer location unless it is an emergency," the Foreign Ministry said.

The areas covered by the level 3 alert in Iran include the border regions of Turkey and Iraq, Sistan-Baluchestan Province, and three coastal provinces along the Persian Gulf: Hormozgan, Bushehr and Khuzestan.

As of Tuesday morning, some 550 South Korean citizens are residing in Israel, 120 in Lebanon and 110 in Iran, excluding embassy personnel, according to the Foreign Ministry.

South Korea's decision to raise travel alerts comes amid growing fears of a widening war in the Middle East.

Although Israel has not claimed responsibility for the assassination of Haniyeh on July 31, which notably occurred just hours after the Israeli assassination of Hezbollah's military chief Fuad Shukr in Beirut, Iran has vowed retaliation.

US Secretary of State Antony Blinken stated on Sunday that Iran and the Lebanese militant group Hezbollah, backed by Iran, could attack Israel within 24 to 48 hours.