Seoul: South Korean police are probing leaflets and Internet messages spreading rumours of imminent war and questioning an investigation into the sinking of a naval vessel which they say could affect Wednesday`s local elections.
The ship sinking has become the top campaign issue, with the liberal opposition accusing President Lee Myung-bak of provoking tension after a decade of warming ties with reclusive and impoverished North Korea.
But polls showed Lee`s uncompromising stand against the North has helped keep support ratings for him near the 50 percent mark in recent weeks.
Lee has vowed to hold North Korea accountable after a team of investigators found Pyongyang was behind the torpedo attack on the corvette Cheonan in March, killing 46 seamen.
North Korea has denied responsibility and accused Lee of fabricating the attack for political gain.
"We are not going to tolerate activities that harm public interest and undermine national integrity through the spread of false information," Seoul police commissioner Cho Hyun-oh said in a message to officers, vowing to punish offenders.
The crackdown on Internet rumour mongering is likely to resurrect a frequent opposition complaint that the government is trampling on democracy and free speech.
Police are on their highest security alert ahead of Wednesday`s voting to choose nearly 4,000 mayors, governors and local representatives, seen as a gauge of support for Lee and his ruling Grand National Party.
Lee is trying to avoid a repeat of massive protests that consumed the first months of his term in 2008 when he failed to contain the spread of information on television and the Internet that experts said hugely exaggerated the health risks of eating US beef amid a mad cow disease scare.
He saw his pro-business reform agenda put on hold as his government battled protests and political fighting in parliament.
An officer at Seoul police HQ said investigators were looking for the source of leaflets that said the results of the probe on the Navy ship sinking had been fabricated.
Some leaflets say the government has been taking pictures of its troops as preparations for their funerals in anticipation of war with North Korea, he said.
"We want to look at how these things are intended to influence the election," the officer, requesting his name be withheld, said.
North Korea has warned of war if the South imposes sanctions as Lee has pledged. Blistering rhetoric from both sides in the past two weeks has unnerved investors in Asia`s fourth-largest economy, worried a major military conflict could erupt.
The two sides are still technically at war decades after the 1950-53 civil conflict which ended with a truce, not a peace treaty.
Lee has established job creation as a top priority for the year and a smooth exit from massive fiscal spending that has pushed South Korea out of the global downturn ahead of peers at a faster pace than expected.
Lee wants to change labour laws to allow employers to keep temporary workers longer to improve labour flexibility. He has also called for corporate tax cuts and changes to the central bank act to allow independent probes into financial companies.
South Korean financial markets close on election day on Wednesday.