NATIONAL CITY (CNS) - A brush fire erupted in a homeless encampment in National City early Friday, authorities said.

The fire off Interstate 805 and state Route 54 was reported at 3:50 a.m., according to the California Highway Patrol.

Crews declared the blaze knocked down at 4:37 a.m., a San Diego fire-rescue dispatcher said.

No injuries were immediately reported.

The cause was under investigation.