The police were quoted as saying that they had received on Friday alone a total of 987 reports of suspicious parcels with cheap products or empty, delivered from abroad, mostly from Taiwan. No hazardous material has been so far found in parcels, but police said it would decide whether to launch an investigation after substance analysis.
The media also cited South Korea's Postal Service as saying that it has temporarily suspended the delivery of suspicious packages amid growing concerns.
A random parcel suspected of containing gaseous toxic materials was delivered to a welfare center for the disabled in the southeastern port city of Ulsan, the report said. Three people were said to suffer dizziness and difficulty breathing upon opening the parcels and were later admitted to hospitals.
Police did not rule out that a toxic chemical agent might have caused the injuries, even though medical tests did not immediately point out what caused the symptom, the media reported. The parcel was sent to South Korea's Agency for Defense Development for analysis.
Another package was found at a postal office in Ulsan on Friday, with similar reports also coming from Seoul, Seoul's suburb of Yongin, as well as Jeju Island, the Haman county in South Gyeongsang Province, and the city of Daejeon, the report said.
Following the incident, the police called for vigilance and said that the color of such packages could be yellow or black with "CHUNGHWA POST" written on them, and the sender could be from Taiwan's Taipei, the report said.
A local news agency cited the Taipei Mission in South Korea as saying that it had found that similar packages were initially sent from China and arrived in South Korea through Taiwan. The media also cited Taiwan's customs agency as saying that it has conducted an investigation into the delivery route of the suspected parcels and shared the results with South Korea's agencies and police.