LOS ANGELES (AP) – Four terminals at Los Angeles International Airport were shut down for about three hours Saturday after a passenger bypassed security at one terminal and a flashlight battery exploded during screening at another, authorities said.

The two incidents a half-hour apart on the busy Labor Day weekend appeared to be unrelated, said FBI spokeswoman Cathy Viray. Several people suffered minor injuries.

The scare at the international terminal came when a flashlight battery in checked luggage exploded as the bag was being hand-searched by a Transportation Security Administration worker, said TSA spokeswoman Amy Von Walter. She said the blast appeared to have been caused by old batteries, not a bomb.

The TSA worker suffered swollen hands and was taken to a hospital, Von Walter said. Several other people complained of ringing in their ears and the passenger whose bag was being screened at the time was being questioned.

About half an hour earlier, security workers reported that a passenger bypassed security at United Airlines’ Terminal 8 by running up a down escalator, Von Walter said. Authorities ordered the evacuation of terminals 6, 7 and 8, which are connected, in order to re-screen passengers.

About 30 departing United flights were listed as delayed, and 17 of the airline’s inbound flights were listed as canceled or delayed. Traffic was diverted from the airport and hundreds of people could be seen standing outside the airport.

The shutdown Saturday followed a bomb scare Friday at Ontario International Airport that prompted the evacuation of 1,000 people for two hours. The suspicious bag that caused it turned out to contain only cosmetics, officials said.

Authorities are especially wary of terrorism at Los Angeles International Airport, among the world’s busiest. It has twice been targeted for attacks – a foiled bomb plot planned for around New Year’s Day 2000, and a shooting at a check-in counter that left three dead on July 4, 2002.