LOS ANGELES -- Passengers were evacuated by inflatable chutes Tuesday after a Honolulu-bound airliner made an emergency landing at Los Angeles International Airport because someone smelled smoke in the cabin.

No sign of fire was found on the aircraft.

Six passengers, including a child, were treated for bumps, bruises and other minor injuries, city fire spokesman Brian Humphrey said.

American Airlines Flight 31 to Honolulu, carrying 188 passengers and six crew members, took off from the airport at 8:48 a.m., American spokesman Tim Smith said.

A short time later, the pilot decided to turn back.

"They had some type of smoke or odor in the cabin," Smith said.

The Boeing 757 landed about 57 minutes later and "the captain elected to declare an emergency and get everybody out of the aircraft via the slides," Smith said.

The passengers were to be placed on another plane to Hawaii but it was unclear how long they would have to wait, Smith said.

Fire crews using thermal imaging cameras scanned the cabin and cargo hold "and thus far found no evidence of an active fire," Humphrey said.

He said the airline, the National Transportation and Safety Board and the Federal Aviation Administration will investigate.

The American flight landed as fire crews were preparing for a publicity event at the airport. Fire trucks were supposed to spray streams of water to welcome an Airbus A380 - the world's largest jetliner - flown by Emirates Airlines.

The American emergency landing delayed the Emirates flight for about 45 minutes, and the water cannon ceremony was scrapped, said Erin Franklin, a publicist for the event.