SEOUL, South Korea — A South Korean lawmaker said Tuesday that North Korean hackers may have stolen highly classified military documents that include U.S.-South Korean wartime “decapitation strike” plans against the North, according to South Korean media reports.

Rep. Lee Cheol-hee, a lawmaker for the ruling Democratic Party, cited unidentified defense officials as saying the hackers stole the plans last year. Neither Lee nor Defense Ministry officials responded to attempts late Tuesday to confirm the stories.

Among the classified plans allegedly stolen from the South were said to be blueprints for targeted attacks by Seoul and Washington to eliminate North Korean leader Kim Jong Un if a crisis breaks out or appears imminent.

The South’s Yonhap news agency said South Korean defense officials said in May that North Korea may have hacked a crucial South Korean military online network but didn’t say what was stolen.

Seoul says North Korea has repeatedly staged cyberattacks on South Korean business and government websites. North Korea routinely denies responsibility.