The US has issued a security alert to its citizens about an "unconfirmed threat" to flights from Guyana.
The US embassy in Georgetown said in a statement that the threat related to Caribbean Airlines flights to the US between Monday and Wednesday.
"Out of an abundance of caution" it advised US citizens intending to travel on those flights to "make alternate travel arrangements".
An airlines spokesman said security had been increased since Friday.
"We are on top of this and flights will continue as normal, but we are taking no chances," Carl Stuart told the Associated Press.
No further details were immediately available.