Two major hospitals in South Korea's capital suspended services to patients on Wednesday in a bid to stop the spread of MERS after four new cases of the deadly virus were reported. The new cases of Middle East Respiratory Syndrome included two who were in the same hospital ward as other patients with the potentially deadly virus, Seoul's health ministry said. The others were a nurse at Samsung Medical Centre in Seoul -- one of the epicentres of the outbreak -- and a relative of a patient who was hospitalised for an unspecified disease in a hospital in Pyeongtaek, south of Seoul, in early June. Out of 179 people confirmed to have caught MERS, five were infected through unknown transmission routes outside hospitals, which have until now been at the epicentre of the outbreak, the ministry said. A total of 27 people have died in South Korea's MERS outbreak -- the largest outside Saudi Arabia -- while about 3,100 people were being held under quarantine at state facilities or at home. Samsung hospital, where nearly 90 patients, visitors and medical staff have contracted the virus, declared a 10-day suspension of most services on June 14 to stem the spread of the virus. But as the number of new infections has continued to grow, authorities have decided to extend the partial shutdown "indefinitely". The outbreak at the hospital, which belongs to South Korea's top conglomerate Samsung group, prompted heir apparent Jay. Y. Lee to publicly apologise for "causing great pain and concern" on Tuesday. Another major Seoul hospital, Konkuk University Medical Centre, on Wednesday also stopped admitting new patients and performing surgery after four cases were reported in recent days. - 'Impact is weakening' - Almost all infections so far have taken place in hospitals and the World Health Organization said it had found no evidence suggesting transmission of the virus outside hospital. Sixteen patients were in critical condition as of Wednesday, the ministry said, while 67 people have recovered and been released from hospital. South Korea's MERS outbreak began on May 20 when a 68-year-old man was diagnosed after returning from a trip to Saudi Arabia. The virus since then has spread at an unusually rapid pace, sparking alarm in the Asia's fourth-largest economy and elsewhere in the region. The outbreak dealt a severe blow to businesses from tourism to retail as people have shunned crowded venues and more than 120,000 foreigners cancelled planned trips to Seoul. South Korea's central bank cut its key interest rate this month in a bid to counter the economic impact of the outbreak, but its chief on Wednesday said it was already starting to fade. "The extent of the fall has declined from the first and second week of the outbreak, which is why we are hoping the impact is weakening," he said in comments carried by the Yonhap news agency. There is no known vaccine for MERS, which has infected more than 1,330 people -- mostly in Saudi Arabia -- in 26 countries since first reported in 2012, according to the WHO.