North Korea fired a short range missile into the East Sea on Friday afternoon, South Korean military sources told local media, the second reported launch of a projectile to occur this week alone.

The missile, which was fired from near Sondok airfield, Hamgyongnamdo, was reported to be a ballistic type, an anonymous military source told ROK national news agency Yonhap.

“Military authorities are investigating the event to identify where it was launched and what kind of missile it is,” the report said. However, the AP news agency said it was unable to confirm the launch from South Korea’s Defense Ministry.

Map shows Sondok airfield, located in the region South Korean media said the ballistic missile was launched from

If true, the launch comes just one day after U.S. President Obama, South Korean President Park and Japanese Prime Minister Abe agreed in Washington, D.C. to continue ratcheting pressure against North Korea’s nuclear weapons program.

North Korea on Tuesday also launched a projectile near its eastern port city of Wonsan, which reports said traveled over a distance of some 200km. An unnamed military source told Yonhap at the time it may have been fired from a new multiple rocket launcher.

The timing of the two launches also comes amid ongoing joint U.S.-South Korean military drills, though the major elements of those have now completed.

Last week North Korean newspaper the Rodong Sinmun detailed what it claimed was presented as the largest-ever long-range artillery exercise to simulate an attack on South Korea, while last Tuesday it published pictures of a “new type large-caliber multiple rocket launching system (MRLS).”

UN sanctions ban North Korea from conducting ballistic missile tests, though artillery and non-ballistic launches are not prohibited.

Main picture: Rodong Sinmun