North Korea test-launched two medium-range ballistic missiles into the East Sea Wednesday morning, South Korea's military said.

"North Korea fired a ballistic missile at 2:35 a.m. and anothermat 2:45 a.m. from the Sukchon region, north of Pyongyang, into then East Sea," the Joint Chiefs of Staff said.

They are estimated to be Nodong missiles as they flew around 650 kilometers, the military said.

If confirmed, it would mark the North's first Nodong missile launch in nearly five years.

The North shot a Nodong missile on July 5, 2006, followed by another launch on July 4, 2009.

North Korea is prohibited from any launch using ballistic missile technology under U.N. Security Council resolutions.

The U.S. Department of Defense said it is aware of "reports that North Korea fired a number of missiles."

"We are closely monitoring the situation on the Korean Peninsula," a Pentagon official said in an email, saying it's the department's formal position on the issue. "We continue to urge North Korea to exercise restraint and take steps to improve its relations with its neighbors. The onus is on North Korea to refrain from provocations."  (Yonhap)