Firefighters battled a blaze in the Upper Newport Bay Nature Preserve on Thursday morning that burned just under an acre, officials said.
It occurred around 6 a.m. near Irvine Avenue and Santiago Drive, not far from where another vegetation fire burned about 1.5 acres last week.
Investigators from Newport Beach Fire Department and the Orange County Fire Authority will be looking for any people or series of circumstances connecting the two incidents, said NBFD spokeswoman Jennifer Manzella.
No damage to nearby homes or injuries were reported.
Manzella said because a Santa Ana wind condition did not materialize, it helped the crews from Newport Beach and Costa Mesa quickly contain the fire. Six fire engines, one fire truck and a battalion chief were dispatched to the scene.
The preserve is about 1,000 acres.