Six wild boars were spotted in eastern Seoul on Tuesday amid rising concerns that the animals are a vector for African swine fever(ASF).

A city squad in charge of preventing the presence of wild boars said they tried and failed to catch the animals for eight hours, beginning at 8 p.m.

The six hogs were first spotted around 6 p.m. near a hospital in the Gangdong district in Seoul, with two of them found at an apartment complex in the Songpa area at around 1 a.m. Wednesday.

The squad and police tried to capture the two boars, but one of them ran towards Olympic Park and the other to a narrow underground area. 

An official from the squad said that the team will return to the underground area on Wednesday with proper equipment after consulting with the Songpa district office. 

Meanwhile, a wild boar was found dead Tuesday night at an underpass in Goyang, Gyeonggi Province. Police suspect it was struck by a vehicle.

Quarantine authorities plan to test the boar for ASF.