The South Korean Defence Ministry couldn't immediately confirm the reports from Yonhap news agency and YTN TV station. Such test firings aren't unusual. North Korea conducted a series of missile and artillery tests earlier this year.
The reports did not specify their sources, and it was not immediately clear what kind of projectiles may have been fired.
The tests, if confirmed, come during an unusually tense period between the Koreas. North Korea has threatened South Korea's leader, calling her a prostitute, and the South has vowed to hit North Korea hard if provoked. There has also been widespread speculation that North Korea is preparing for its fourth nuclear test.