LOS ANGELES (AP) -- A loud auto crash that some passengers thought was shots being fired and an anonymous call reporting a gunman prompted evacuations Friday night at two terminals of Los Angeles International Airport, officials said.

A woman driving on the airport's arrivals loop at about 7:30 p.m. lost control of her SUV, hitting another woman who was walking on a sidewalk before slamming into a parking garage across the roadway from Terminal 5, Los Angeles police Sgt. Mark Guardado said.

Rattled nerves remained at the airport after a shooting exactly three weeks ago in which a gunman killed a security officer and injured three other people.

"With what recently just occurred here, everybody's still a little bit on edge," Guardado said.

Sounds from the crash spurred reports of gunfire among the passengers inside the terminal, many of whom ran outside, airport police Chief Patrick Gannon said at a media briefing.

"It was determined relatively quickly that there was not a shooting," Gannon said.

Both women in the crash were injured, the pedestrian seriously, Guardado told KTTV-TV. The wreck was caused by a medical emergency with the driver, Gannon said. Details on women's conditions were not immediately available.

Meanwhile in neighboring Terminal 4, airport police received an anonymous call just after the crash reporting a gunman at a specific gate, Gannon said.

That prompted police to order a complete evacuation of both terminals while they investigated, but again no gunman was found and the terminals were deemed safe Gannon said.

Evacuated passengers, an estimated 2,000 in all, were allowed to return, but had to be rescreened by security, causing a huge bottleneck of people trying to get back in.

"It took us a couple of hours to clear those terminals," Gannon said. "It created quite a disturbance here at the airport

The false alarms made trouble for travelers on a busy Friday night, backing up street traffic and slowing down air traffic. Terminal 4 is home to American, American Eagle and Qantas airlines. Terminal 5 is occupied solely by Delta Airlines.

An estimated 4,600 passengers were affected by the incidents, LAX spokeswoman Nancy Castles said.

Delta and American airlines reported a combined total of 60 delayed flights, both inbound and outbound, but no cancellations.

Four arriving flights were diverted to other regional airports but were expected to refuel and continue to LAX, Castles said.