Law enforcement agencies in several major US cities have issued alerts advising residents to be vigilant in the wake of the US strike against Iran’s top general as officials said they were stepping up security efforts at sensitive locations.

In New York City, Mayor Bill de Blasio announced he was consulting with city officials about steps the the police department will take to protect key locations “from any attempt by Iran or its terrorist allies to retaliate against America”.

Los Angeles, home to a sizable US-Iranian population, also issued an alert hours after the US strike on Qassem Suleimani, asking “every Angeleno to say something if you see something”.

The communication was followed by a second Los Angeles police department (LAPD) message, posted on Twitter, that also emphasized there was no current threat.

“While there is no credible threat to Los Angeles, the LAPD is monitoring the events developing in Iran. We will continue to communicate with state, local, federal and international law enforcement partners regarding any significant intel that may develop.”

The warnings came as the US state department urged its US citizens to leave Iraq “immediately”.

The US embassy in Baghdad, which was attacked by Iran-backed militiamen and other protesters earlier this week, is closed and all consular services have been suspended.