A fire causing about $20,000 in damage to a Lagoon Drive restaurant last night was intentionally set, a Honolulu Fire Department spokesman said today.

The fire began at about 8:40 p.m. in the kitchen of Lagoon Chinese Food, 498 Lagoon Drive, said Honolulu fire Capt. Terry Seelig in an e-mail. The case has been referred to police.

Within 20 minutes, firefighters extinguished the fire, which damaged the eatery’s kitchen. The restaurant was closed at the time, Seelig said.

A voice message at the restaurant said it is closed today.