The first batch of South Korean medical workers returned home Monday after treating patients in Ebola-hit Sierra Leone for about one month, officials at the foreign ministry said.

The nine doctors and nurses did not show any symptoms of infection for the deadly virus, but they will be placed under a three-week quarantine at an unknown place to undergo further monitoring, they said.

The first team, which initially consisted of 10 members, kicked off their mission to Goderich, near Sierra Leone's capital of Freetown, in late December.

But one staff member was moved to a German hospital in early January after the worker's index finger came in contact with a needle while collecting blood from an Ebola patient. The worker was discharged from the hospital after being confirmed clean last week.

The second batch of nine medical workers will start their activity in the West African country Monday (local time), officials said. The remaining 11 medical staff will depart from Seoul in early February.

South Korea has joined global efforts to fight Ebola by sending medical workers and offering a combined US$12.6 million in assistance. The virus is estimated to have killed more than 8,600 people since the outbreak in December 2013, according to the World Health Organization. (Yonhap)