Police said Sunday they have received intelligence claiming that an African group linked to the Islamic State has threatened to carry out a terrorist attack on a store in a posh Seoul district.

In a post on social media, the Mali group said they would attack a shop near COEX, a large shopping complex in the wealthy district of Gangnam, a police official said, asking not to be named, adding there was no mention of explosives being involved.

The official, however, said the attack appeared highly unlikely.

"The store mentioned is a supermarket. In Africa, supermarkets are apparently some of the most crowded places," the official said.

"The group clearly doesn't understand the way things work in South Korea, so the chances of an attack appear slim."

The attack is said to be planned for Sunday, though no specific time has been mentioned.

Police said they have beefed up security in the area to prepare for contingencies. So far, no signs that would raise suspicions of an attack were found.

"We can't 100 percent rule out the possibility, though, so we've strengthened security," the official said.

The intelligence was received through the National Intelligence Service, which cited information from the Ministry of Foreign Affairs.

 An NIS official said on condition of anonymity that the spy agency was "confirming the facts and preparing for all possibilities." (Yonhap)