LONDON/MOSCOW/BEIJING, May 23 (Yonhap) — Kim Jong-chol attended an Eric Clapton concert in London for the second time this week, but where the brother of North Korean leader Kim Jong-un headed Saturday remained unknown. He had been scheduled to arrive in Beijing on Saturday from Moscow on his way to Pyongyang, a source with knowledge of the stopover said. However, the name of Jong-chol was not on the registry of the flight from London to Moscow, according to the source. He also wasn’t seen at the Beijing airport Saturday.