A fire consumed a house under construction at 108-49 66th Ave. in Forest Hills on Nov. 17. Sources said that investigators have surveillance video showing a man entering the site shortly before the fire broke out. View Full Caption 112 Precinct/Twitter

QUEENS — Investigators probing a recent rash of suspicious fires in Forest Hills have surveillance video showing a man “looking like a ninja,” entering a construction site where one of the blazes broke out, police sources said.

The man wearing all black is seen scaling a wall at 108-49 66th Ave., where the fire erupted on Nov. 17 and spread to two nearby homes, sources said.

The suspect carried a backpack which investigators suspect may have contained incendiary materials used to start the fire, sources said.

According to the 112th Precinct, which covers the area, six of the seven recent fires in the area have been deemed suspicious.

All the suspicious fires broke out at vacant buildings that were being renovated or under construction.

The first blaze erupted on Oct. 20 at the former Parkway Hospital, which has been vacant since it closed in 2008.

Most of the fires were residential and clustered in the area between Jewel and 65th avenues and between Queens Boulevard and the Grand Central Parkway, in the section of Forest Hills known as Cord Meyer.

Only one blaze happened in a different portion of the precinct, on Woodhaven Boulevard.

No injuries were reported in any of the suspicious incidents.

In the past two decades, the Cord Meyer area has seen an influx of new large and expensive homes, built mostly by Bukharian immigrants. The new homes contrast with other older houses in the neighborhood which often feature Tudor and Georgian architectural styles.

Sources said that investigators are looking into a variety of possible motives, including anger against the new homes that some locals say do not match the neighborhood. Insurance payout and circumventing zoning regulations are also considered among possible motives, sources said.

A spokesman for the Fire Department said Tuesday that the string of fires is “still under investigation,” but did not elaborate.