SEOUL, SOUTH KOREA - North Korea will close two of its air routes from April 4 - 8 for its planned rocket launch.

The North's air route traffic control center informed its South Korean counterpart on Saturday of the temporary closure, the South's Ministry of Land, Transport and Maritime Affairs said in a statement.

The two affected air routes, linking the North to the Russian port city of Vladivostok and to Japan, will remain closed for five hours from 11am daily during the five days, the statement said.

On Saturday, North Korea restored a severed military communication channel and reopened the border for South Koreans visiting a joint industrial complex, following the conclusion of a US-South Korean military exercise.

'The military communication line was reopened before 8am, and North Korea later sent a letter of approval for border traffic by fax,' Unification Ministry spokesman Kim Ho-nyoun said.

North Korea cut off the only remaining phone and fax channel and shut the border as the joint military drill got underway on March 9. It had said the suspensions would be effective throughout the joint drill period.

As the allies wrapped up their 12-day Key Resolve and Foal Eagle drill on Friday, the North Korean military sent a letter to South Korea saying it would restore the communication line.

During the joint drill, North Korea sealed the inter-Korean border three times, with the latest closure on Friday. The measure threatened production in the joint industrial complex in North Korea's border town of Kaesong, as hundreds of South Korean workers and cargo trucks were forced to cancel their trips.

With the border reopened, hundreds of South Korean workers and trucks will resume trips to the Kaesong complex, the spokesman said. -- THE KOREA HERALD/ANN