The nationwide "creepy clown mask" phenomenon has struck in San Francisco, with the appearance of three armed men clutching clown masks at the Westfield San Francisco Centre mall downtown.

As the Examiner reports, the three men were in the emergency stairwell at the mall yesterday around 3pm when they were spotted by security guards making the rounds. Two of the men were clutching clown masks that an SFPD spokesperson described as "very scary," while the third had a gun.

The armed man did not point his the weapon at the security officers. Instead, all three men fled the building on foot at the Powell and Market exit. The guards immediately contacted police, but as of last night, the suspects remained at large. 

While there have been reports of "creepy clowns" all over the country, particularly on the East Coast, most of the threats have been hoaxes. Earlier this month, a man in a clown mask was spotted on a 5-Fulton bus, but he only made obscene gestures, and didn't harm anyone.