The leader of a paramilitary arm of Iran's Revolutionary Guards has allegedly ordered militia groups in Iraq to strike U.S. interests in the event of an American military incursion into Syria, the Wall Street Journal reported.

The message from Qasem Soleimani, head of the Qods Force, as the unit is known, was intercepted by U.S. officials as it was sent to Shiite groups in the region, which are already sympathetic to Syrian president Bashar al-Assad's government.

Officials argued that Soleimani encouraged the militants to be ready in case of a U.S. attack, as the issue continues to be debated before going to a vote by American lawmakers, but did not identify any potential targets mentioned in Soleimani's directive.

The Journal also reported that the State Department issued an alert on Thursday advising against nonessential travel to Iraq, which included a warning about terrorist activity "at levels unseen since 2008."

[Image via Agence France-Presse]