KITTERY – The discovery of a leak in a 30,000-gallon propane tank prompted the evacuation of a nearby factory building Tuesday.

The leak was discovered in the tank used by Watts Fluid Air around 9:30 a.m., said fire Chief Dave O’Brien. Two dozen firefighters and four firetrucks were at the scene at the intersection of Cutts Road and Route 1 as propane was offloaded onto tanker trucks.

When most of the liquid was removed, the remaining gas will be burned off and repairs will be able to be made to the tank, O’Brien said.