Tourists have been cut off from visiting the Demilitarised Zone (DMZ) separating North and South Korea in an effort to contain an outbreak of African swine fever.

Key points: Several cases of swine fever have been reported in the northern parts of South Korea

Several cases of swine fever have been reported in the northern parts of South Korea Attempts to control the disease have been complicated by a 1953 ceasefire agreement

Attempts to control the disease have been complicated by a 1953 ceasefire agreement The Odusan Unification Tower observatory is as close as tourists will get to North Korea

South Korea's unification ministry yesterday announced it was stopping tourists from entering the inter-Korean border village of Panmunjom in the DMZ amid fears the contagious disease could spread.

"The decision is part of the unavoidable, intensified quarantine measures to stem the spread of ASF [African swine fever] to other regions," they said in a statement.

The Government said it "will exert utmost efforts to resume Panmunjom tours at the earliest possible date".

African swine fever is fatal in pigs but is not harmful to humans.

Several cases have been reported in the northern parts of South Korea after it spread from China to North Korea.

DMZ tour guide Erica Kim said she had to cancel tours for 8,000 visitors on October 1. ( ABC News: Erin Handley )

DMZ tour guide Erica Kim told the ABC she had to cancel tours for thousands of visitors at short notice.

"Yesterday I was told the DMZ will be shut down due to the Africans swine [fever]," she said.

"We can't pass the civilian control zone [near the DMZ]."

"Because the DMZ is a top tourist destination — there are millions of tourists to the DMZ each year — [the Government is] concerned the disease could spread to the other countries."

'We can't shoot them'

The entrance to the DMZ next to Dorasan station has been closed to tourists. ( ABC News: Jarrod Fankhauser )

North and South Korea have been separated by a 4 kilometre-wide strip since the Korean War started in 1950. A ceasefire was signed in 1953, but no peace treaty has been signed to officially end the war.

Last week, Reuters cited an official saying South Korean soldiers manning the DMZ had been ordered to chase and capture wild boars at the border in a bid to contain the outbreak.

But he said troops were unable to fire their weapons at the pigs, as it would break the ceasefire.

"We can't shoot them because it would be a violation of the armistice agreement," the official told Reuters.

Ms Kim said tourists can usually get within 170 metres of the isolated country inside tunnels built by North Korean soldiers, but for now the Odusan Unification Tower observatory is as close as tourists will get.

A handful of buildings on North Korean territory can be sighted across the Han River from the observatory.

She said the last time the DMZ was closed due to contamination fears was in 2015 during an outbreak of MERS, or Middle East respiratory syndrome.

Erin Handley was in South Korea for the Walkley Foundation Australia-Korea media exchange program.