South Korean authorities are investigating Samsung, after assessing that two workers at one of the tech giant’s plants were exposed to radiation.

The two patients, who are hospitalized, were showing “abnormal” symptoms of radiation exposure in their fingers, the Nuclear Safety and Security Commission in South Korea said in a Google-translated statement on Wednesday.

The patients’ general blood tests produced a normal result, according to the authorities.

Samsung was not immediately available for comment when contacted by CNBC.

The prospective radiation exposure incident took place at Samsung’s Giheung plant, which is around 25 miles south of the South Korean capital of Seoul.

The authorities said they have suspended the use of the machine responsible for the incident. The exact cause of the radiation exposure is not known at this time, with the Nuclear Safety and Security Commission carrying out an ongoing probe.

The commission said it will take further steps if any violations of safety laws are confirmed.