The Department for Transport disclosed the action but gave no information on the security issues and didn't identify the locations involved.
It said that "following careful consideration, the department has restricted the number of sites in the U.K. at which UPS Ltd. are permitted to screen air cargo until it has satisfied current security requirements."
The department said it could not give details of the sites for security reasons.
UPS told customers Friday that shipments from Britain were being delayed but did not give further details.
The vulnerability of air cargo to terrorist attacks is a major worry for international security agencies.
Last October, two bombs were sent disguised in toner cartridges on cargo flights from Yemen bound for the United States. One was discovered at a FedEx cargo facility in Dubai, the other at a UPS depot at England's East Midlands Airport, 100 miles (160 kilometers) north of London.
Officials said the bombs were viable and could have exploded in mid-flight. Al-Qaida was blamed for the plot.
Britain suspended all unaccompanied air cargo from Yemen and Somalia after the thwarted plot, and officials in Britain, the United States and other countries promised to tighten air cargo security.
Despite the heightened alert, in March someone shipped a hoax bomb - which had a timer, wires and a detonator - to Turkey via the UPS office in London.
