The military is beefing up its vigilance in case North Korea could stage provocations in a bid to divert international criticism over the apparent assassination of its leader's half brother, Kim Jong-nam.

A defense official said Monday the South Korean military has strengthened the surveillance on the North although no unusual moves are being detected.

While noting that the North could try to turn around the situation with additional provocations, the official explained that the military is also preparing for possible terror attacks in the rear areas.

Acting President Hwang Kyo-ahn called for tighter security measures to prepare against possible provocations by the North in a National Security Council meeting on Monday. 

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