A poster for "Northern Limit Line." (NEW)

A film depicting a bloody inter-Korean naval clash 13 years ago has exceeded 2 million in attendance in the shortest period of time for any Korean film this year, data showed Thursday.

"Northern Limit Line" hit the milestone Wednesday, seven days after it opened, according to the computerized box-office tally from the Korean Film Council. It has been seen by 2,068,395 people through that day, the data showed.

It took the same period of time for "Masquerade" (2012) and "Ode to My Father" (2014) to surpass the 2 million mark. The two films went on to draw 12.3 million viewers and 14 million viewers nationwide, respectively.

"Unlike other hit movies that opened on traditional holidays or at year-ends, the 'Northern Limit Line' is having exceptional success," its distributor, NEW, said in a release.

The movie depicts the naval skirmish off South Korea's border island of Yeonpyeong on June 29, 2002, which left six South Korean sailors dead and 18 others injured. (Yonhap)