Britain has banned the cargo shipping company UPS from using some of its facilities out of security concerns.

The Department for Transport said in a statement Friday it had “restricted” the number of sites where UPS could screen its air cargo until it satisfies current security requirements.

It did not supply details on the sites.

UPS was not immediately available for comment on the restrictions.

Britain in November announced tougher screening of air cargo in response to the discovery of package bombs on U.S.-bound planes.