A suspect is in custody after a United Airlines flight from Anchorage, Alaska, to Denver, Colo., was diverted early Saturday morning to the Vancouver International Airport because of "security concerns," said police.

"There was a legitimate security concern on board the flight and we do have a male in custody at this time," said Cpl. Dennis Hwang of the RCMP in Richmond, B.C.

United Airlines flight 1104 departed Anchorage a little before midnight, and was set to land in Denver shortly after 6 a.m., local time.

It landed in Vancouver shortly after 4 a.m. PT.

A spokesperson wouldn't elaborate on the nature of the security concerns, referring questions to the RCMP.

"Specifics about the exact nature of the security concern are under investigation but we can confirm this appears to be an isolated incident in which security protocols were enacted, and the Criminal Code investigations remains active and ongoing," said Richmond RCMP in a release.

In a statement, a United Airlines spokesperson said the Boeing 737 was carrying 131 passengers and a crew of six.

Passengers were escorted from the flight and screened for security.

Five ambulances were called to the airport, said a BC Ambulance spokesperson, but there were no injuries.

A statement from the airline said passengers were booked on other flights to resume their travels.

There was no impact to operations at the Vancouver International Airport.