MANHATTAN — Multiple manhole blasts caused a fire near Manhattan's Union Square Friday morning, prompting traffic delays and a temporary closure of The Strand bookstore, according to officials.

Multiple reports on social media around 7:50 a.m. indicated people in the area heard an explosion.

Multiple manhole blasts occurred near Broadway and East 12th Street, bordering the Greenwich Village and East Village neighborhoods, FDNY says.

Fire officials responded to a subsequent "commercial fire" next to The Strand bookstore.

Firefighters were seen walking through the bookstore as of 8:35 a.m., but active flames were not visible.

Bookstore officials later confirmed the store is temporarily closed, although it is not clear if it will remain shuttered throughout the day.

Hi Strand fam, thanks for checking on us this morning. The Strand (& books) are safe!! We are currently closed, stay tuned for updates. ❤️ — Strand Book Store (@strandbookstore) March 31, 2017

NYC's emergency notification system tweeted extensive traffic delays are expected in the area.

Huge explosion sound on Broadway and 12th street #NYC — Amy Mariea Bowllan (@abowllan) March 31, 2017