A mysterious explosion and fire at an arms development site in central Israel left one person moderately injured Monday night.

The blast took place at an Israeli Military Industries factory in Ramat Hasharon, outside Tel Aviv.

Firefighters called to the scene put out the blaze.

An initial investigation found that the fire was started by an explosion on a production line. The cause of the blast was not known and IMI said it was looking into the incident.

The injured man, reportedly in his 20s, was taken to Meir Hospital for treatment.

The site covers over a thousand acres and produces various kinds of ammunition and other military hardware.

In 1992, some 10 tons of explosives blew up at an IMI storehouse in Nof Yam. Two people were killed, and over 60 injured.