The US has banned toner and ink cartridges from passenger aircraft in the wake of last month’s bomb plot.
In addition, cargo flights from Somalia and Yemen are banned, Homeland Security Secretary Janet Napolitano said.
High risk cargo will receive extra screening and parcels must be screened and certified to have come via an established shipper, she said.
The strictures come after bombs hidden in cartridges were intercepted on route from Yemen to the US in cargo planes.
“The safety and security of the American public is our highest priority,” Ms Napolitano said in a statement.
“The threats of terrorism we face are serious and evolving, and these security measures reflect our commitment to using current intelligence to stay ahead of adversaries-working closely with our international, federal, state, local and private sector partners every step of the way.”
Ms Napolitano said US Transportation Security Administration officials had met in Yemen with officials there, in an effort to enhance Yemeni security enhancements so the cargo ban eventually can be lifted.
The printer cartridge ban affects cartridges over 16 ounces.
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