Spectators watch as the Norwegian Joy cruise ship makes its way down the Ems River near Emden in northern Germany on March 27, 2017.
CNN  — 

Six passengers aboard a cruise ship docked in Los Angeles were treated for flu-like symptoms Sunday, according to the city’s fire department.

The Norwegian Joy cruise ship docked at the Port of Los Angeles around 6 a.m. PT on the return leg of a trip to the Panama Canal, according to information from Ports America and Norwegian Cruise Line. All six passengers wanted medical assessment for an “unspecified and apparently non-life threatening illness,” the Los Angeles Fire Department said.

“During Norwegian Joy’s Panama Canal sailing, a few guests on board experienced a stomach related illness. To mitigate any impact of this rare occurrence, we implemented stringent sanitation procedures,” according to a statement Norwegian Cruise Line emailed to CNN.

Of the six passengers treated, four were taken to area hospitals, according to the LAFD.

The Norwegian Joy was built in 2017 and has a maximum capacity of 3,804 passengers plus a crew of 1,700, according to the Norwegian Cruise Line website. The company offers cruises to the Panama Canal via 16 to 20-day cruises, its website states.