Tokyo-Yokohama remains the world's largest science and technology cluster in 2024, though clusters in middle-income economies are seeing the fastest growth in the innovation sector, the United Nations said Tuesday.

The U.N.'s World Intellectual Property Organization said Shenzhen-Hong Kong-Guangzhou remained in second place, while Beijing overtook Seoul to grab third place.

WIPO, the U.N. agency dealing with patenting and innovation, said that China, for the second consecutive year, led with the most clusters in the top 100, at 26 (up two), followed by the United States with 20 clusters.