Prosecutors on Tuesday raided the headquarters of the nation's main intelligence agency in connection with suspicions that the organization attempted to influence public opinion ahead of last year's presidential election.

A team of some 25 prosecutors and investigators seized digital files, internal documents from an anti-North Korea psychological warfare team at the National Intelligence Service (NIS), they said.

Allegations have been raised that the NIS extensively and systemically intervened in the presidential election by using its agents at the team to post a slew of politically sensitive comments on the Internet against the opposition candidate to sway public opinion ahead of the December race. (Yonhap News)