Pop star Rihanna is facing an anxious wait ahead of her concert in Winnipeg, Canada on Monday night (25Mar13) after her production trucks were stopped by border officials en route from the U.S.

Staffers transporting the Umbrella hitmaker's stage and props from her last Diamonds tour stop in St. Paul, Minnesota to Winnipeg's MTS Centre, where she is due to perform on Monday, are being held by immigration authorities - and the incident could cause serious delays or even the possible cancellation of Rihanna's show.

The singer took to her Twitter.com blog to share news of the delay with fans, writing, "They held my trucks at the border!!! This is not a good look for Winnipeg! My stage is in those trucks, disassembled! This means, the entire production could potentially start at a later time."

Rihanna, who was not travelling with the convoy, arrived at the MTS Centre two hours later and tweeted, "My bus and I are at the venue! Still no trucks!!!"

It's the second time in less than a week that Rihanna's tour has run into customs trouble - a fleet of her tour buses was stopped and searched at the Canadian/U.S. border in Michigan last week (20Mar13) after authorities found one passenger in possession of marijuana.