Note 7 owners must wait to receive packaging that meets regulatory guidelines before either FedEx or UPS will take them. Samsung and Verizon Communications said they're providing customers in the US with these fireproof prepaid delivery packages, which the US Department of Transportation has approved. Even then, FedEx Ground won't accept phones from individual customers or from any other type of store, including those with FedEx counters or drop boxes.

Customers can also return the phones in person to their wireless carrier. Samsung said in a statement it also offers the option for customers to schedule a pick-up.

Total ban

The UK's Royal Mail said earlier it would ban Note 7 shipments entirely. Customers sending packages through the mail or via Royal Mail's Parcelforce courier service will be asked to detail what's inside, to prevent faulty products from slipping into delivery vans, the London-based mail carrier said in an emailed statement.

The decision by Royal Mail hampers compliance with Samsung's global recall of all Note 7s following repeated reports of the smartphones catching fire. The South Korean manufacturer said in a statement that it's arranging home collections using UK Mail Group, the delivery service German carrier Deutsche Post AG agreed to buy in September. However, this applies only to customers who bought a device in the UK from Samsung's online store.

Deutsche Post's DHL express-delivery division is still transporting the devices following a suspension of a few days in late September while it sought clarification from Samsung on ways to maintain safety rules, Dirk Klasen, a spokesman in Bonn, said by phone.

Samsung has yet to issue any information about the cause of the latest incidents with its flagship Note 7 phone. Government investigators believe that a separate problem may have caused the overheating of the devices delivered as replacements for the recalled version, a person said. The US Consumer Product Safety Commission and Samsung have not agreed to expand the initial recall of the first Note 7 batch announced last month.

The company said that a thorough investigation takes time, and it would be premature to speculate on the outcome. Samsung said it has a process to safely dispose of the phones after receiving them that is in accordance with government regulations, without providing specifics.

Samsung cut its projection for third-quarter operating profit by $US2.3 billion ($3.04 billion) on Wednesday after deciding to end Note 7 production this week.

- with assistance from Nate Lanxon Scott Moritz and Alan Levin

Bloomberg