Authorities in Guyana and the U.S. Embassy there have warned of an unspecified "threat" to Caribbean Airlines flights out of the South American nation.
Extra security measures were put in place at Cheddi Jagan International Airport outside the capital Georgetown, but the Trinidad and Tobago-based airline was operating normally out of Guyana on Monday with a flight to New York departing at dawn.
"The officials assessed the threat and put in place a number of measures to prevent any untoward occurrence," the airport authority said in a statement late on Sunday.
"Passengers and other airport users are asked to be on the lookout for any suspicious activities or occurrences and report same to an airport security official," it continued. "A heightened security posture will remain in place over a number of days until such time as the threat is no longer deemed valid."
Guyana is a former British colony on the northeast shoulder of South America.
The U.S. Embassy in Guyana warned citizens not to use Caribbean Airlines until the middle of the week.
"Out of an abundance of caution, the embassy advises all U.S. citizens in Guyana traveling on Caribbean Airlines to the United States from Monday, Feb. 10 through Wednesday, Feb. 12, 2014, to make alternate travel arrangements," it said.
On its web site, Caribbean Airlines said its planes were leaving normally, but extra security was in place.
"We thank the traveling public for their understanding of any inconvenience as special security measures have been put in place," it said in a statement.
The airline says its 21 aircraft serve 16 markets in the Caribbean, South America and North America.