It’s suspicious, is all:

Police closed most of Union Square Park for more than an hour yesterday while they investigated several small piles of what a park security guard said was later identified as bleached flour.

At 9:30 a.m., park security officers discovered nine piles of a white powder scattered around the park and called police to investigate, the security officer said. Police cordoned off three-quarters of the park and ordered a quarter of the stalls that are part of the park’s holiday craft market to close during the course of their investigation.

Once the substance was identified, police officials sprayed a mixture of soap, water, and bleach on the crushed piles. One official said the powder piles may have been a prank, but they are investigating further.

Location Scout: Union Square Holiday Market.