North Korea has declared a no-sail zone off its east coast in a sign it could be preparing a missile launch, Yonhap news agency reported on Sunday.
The warning covers all movement of ships from Nov. 11 to Dec. 7 for an area off the North's central coast, the agency said, quoting an unnamed government source, NBC News reported.
"We are observing closely whether North Korea will launch a Scud missile or a new model of ballistic missile because the area under the warning is quite vast," a government source was quoted as saying by Yonhap.
South Korea's defense ministry declined to confirm whether a no-sail warning had been issued.
The prohibited area is near the eastern port city of Wonsan where leader Kim Jong Un's family compounds are located, according to media reports.