A rapidly growing vegetation fire engulfed several structures Tuesday afternoon in Morgan Hill, officials said.

The nearly 30-acre blaze was reported just before 2 p.m. near the intersection of Hale and Live Oak avenues, just west of Monterey Road, a rural area with few homes, said Pam Temmermald, a spokeswoman for Cal Fire.

Fire crews were battling the conflagration, which was growing at a “dangerous rate of speed,” Temmermald said.

There were no reports of injuries and no immediate information on how many structures involved.

The cause of the fire is under investigation.

Sarah Ravani is a San Francisco Chronicle staff writer. Email: sravani@sfchronicle.com Twitter: @SarRavani