JAKARTA: Beijing insisted Monday a Chinese boat detained close to Indonesian islands had been fishing legally, in a fresh flare-up of tensions between the countries in the South China Sea. The Indonesian navy seized the Chinese boat in waters near the Natuna Islands on Friday for allegedly fishing illegally, the military said. The boat was towed to shore and eight Chinese crew members have been detained. Jakarta and Beijing have clashed before over the islands on the southwestern fringe of the disputed South China Sea, where China is also at loggerheads with several other countries because of its overlapping claims. Chinese foreign ministry spokeswoman Hua Chunying insisted the detained vessel had been operating legally.