(Reuters) - Hong Kong warned its residents on Friday to avoid “non-essential” travel to Iran, days after Tehran launched missile attacks on U.S.-led forces in Iraq in retaliation for a U.S. drone strike that killed an Iranian commander.

Issuing a red alert, which implies a significant threat, on travel to Iran, Hong Kong’s Security Bureau said residents should avoid non-essential travel, including leisure travel. “Those already there should monitor the situation, exercise caution, attend to personal safety and avoid protests and large gatherings of people,” it said in a statement.

The bureau added that Hong Kong residents should avoid all travel to Iran’s border with Afghanistan, Iraq and Pakistan, citing a volatile security situation.