[UPDATE BELOW] We're getting reports that a possible gas leak and/or explosion has prompted the evacuation of buildings in Brooklyn Heights near Borough Hall and Court Street. According to some reports, at least five manhole covers have blown, and subway stations at Borough Hall and Court Street in Brooklyn have been evacuated and closed. One reader just sent us this email:

2 3 4 and 5 service from Brooklyn to Manhattan is currently suspended in both directions it seems. Borough hall subway station is swarmed with fire engines and firemen, one of whom told me there was a possible explosion in the tunnel between Brooklyn and Manhattan. The R may still be running, and they couldn't give an estimate for when train service would be restored.

And via Gothamist contribute: "So MAJOR EXPLOSION just outside my build. I thought my building was about to fall over. Everyone is okay. Thanks Goodness! But I am being asked to leave my building. What the heck!" A command post is being set up at Columbia Place & Joralemon Street in Brooklyn, and we'll update as more information becomes available.

UPDATE:The FDNY has requested an additional 2 trucks and the HAZMAT battalion. And the city's Office of Emergency Management announced through Notify NYC: "Emergency personnel are on the scene of multiple manhole fires near Joralemon Street and Columbia Place in downtown Brooklyn." (They're also on Twitter.)

UPDATE 2: More FDNY units are responding, and we're hearing over the newswire that there are "active manholes exploding" and the fire is still not under control. A police officer at the scene told us that after the manhole explosions, there was a transformer explosion, but this has not been officially verified and we're waiting for a statement from NYC Transit. Reader J.Matthew Cahill, who is at the scene, tells us "There are trains stalled on both platforms, and they're roping off the Borough Hall turnstiles and redirecting people to the A/C to get into Manhattan." The Borough Hall train station on Court Street & Joralemon is without power, and all hands are being called to respond.

UPDATE 3: A spokesman for NYC Transit writes: "We did resume 2/3 service with delays between Borough Hall and Wall St, but 4/5 remains out between Atlantic Ave and Fulton St. Started as reports of loss of power, then we were informed of Con Ed feeder problems in area. We had no injuries and I know of no explosions within the system.

Commenter Longacre points out that the FDNY command center is set up by the NYCT IRT Substation on Willow Place in Brooklyn Heights. And a local resident who would only give us his first name (Bob) says, "They evacuated our building and there's a big crater surrounding a manhole that exploded near Joralemon and Willow. I heard two other explosions this morning, too."

At around 1:30, a tipster told Brooklyn Heights Blog: "There is an active manhole fire on Joralemon at the corner of Willow Place. Smoke was coming out of the manholes and the street was being closed off as I approached. Suddenly there was an explosion and I saw two manhole covers pop 8-10 feet in the air. I could see the bottom side of the covers and I was standing uphill the manholes! Firefighters are checking the surrounding basements for potential gas leaks."

UPDATE 4:18 p.m.: It's being reported that the cause of the incident was a private contractor installing gas service to a residence in front of the MTA substation at 25 Willow Place. According to Yeshiva World, the contractor struck a NYCT electrical line, causing multiple manholes to explode in the vicinity of 62 Joralemon Street and resulting in a temporary power disruption to the NYCT Borough Hall Station. Below, video from Fox 5's helicopter: