A North Korean navy

North Korea declared a no-sail zone over the East Sea, raising concerns over another missile launch.
North Korea put the no no-sail zone over a specific area of the East Sea on April 1, Yonhap News Agency reported quoting an unnamed government official.
The source said that there was no end date specified.
Another source told Yonhap that several TEL (Transporter Erector Launcher) vehicles carrying Rodong missiles were identified in the east coast area of North Korea.
Establishment of no-sail zone is usually related to missile launches, one military expert said.
“(North Korea) usually declares no-sail zones in order to prevent possible damage to vessels which pass under the missiles’ flight course,” a former ROK military intelligence officer told NK News on the condition of anonymity.
North Korea didn’t notify its declaration of a no-sail zone to the International Maritime Organization nor South Korea, a press officer of Seoul’s Ministry of National Defense said in a conference on Monday.
North Korea test-fired five short-range projectiles in total last week. It also launched two missiles in the beginning of March, which coincided with the joint ROK-US military drills.