Image copyright AFP Image caption Body heat scanners are among the tools South Korea is using to control the spread of Mers

South Korea's outbreak of Middle East Respiratory Syndrome is "large and complex" and more cases are expected, World Health Organization experts say.

But while it was premature to declare the outbreak over, the WHO said it had "found no evidence" of the Mers virus spreading wider in the community.

About 140 people have been infected since the start of the outbreak last month. Fourteen are known to have died.

Experts also urged the South Korean government to stay vigilant.

Media playback is unsupported on your device Media caption Mers virus explained in 60 seconds

Middle East Respiratory Syndrome (Mers)

Mers is caused by a new type of coronavirus, a type of virus which includes the common cold and Sars (severe acute respiratory syndrome).

First cases emerged in the Middle East in 2012, and the first death in Saudi Arabia in June that year.

It is not known for certain how it is transmitted. It is possible the virus is spread in droplets when an infected person coughs or sneezes.

Patients have a fever, cough and breathing difficulties, but Mers can also cause pneumonia and kidney failure.

Approximately 36% of reported patients with Mers have died - there is no vaccine or specific treatment.

Mers: The new coronavirus explained

How South Korea is coping with outbreak

Speaking in Seoul after a week-long investigation, the WHO's Keiji Fukuda said: "Because the outbreak has been large and is complex, more cases should be anticipated."

He added: "At present the mission has found no evidence that there is ongoing transmission within the community."

All of South Korea's cases have been linked to health facilities, but the WHO urged the government to continue to maintain strong control measures, thoroughly tracing infected people's contacts and preventing suspected patients from travelling.

A number of factors may have contributed to the spread of the disease in South Korea so far, the WHO said, including:

Overcrowded emergency rooms and hospital wards

The habit of "doctor shopping" - visiting several facilities for the same complaint

Doctors unfamiliar with the disease

About 2,900 schools were closed and 3,680 people were isolated as of Friday after possible contacts with those infected.

Earlier this week, South Korea's central bank cut interest rates to a record low in a move seen as an attempt to stem the economic fallout from the outbreak in Asia's fourth largest economy, which was first reported last last month.

The outbreak is the largest outside Saudi Arabia, where the disease was first identified in humans in 2012.