GUANGZHOU - The 21 Vietnamese fishermen detained for illegal fishing operations in China's territorial waters have received humanitarian care from the Chinese side, a Chinese fishery official said Tuesday.

One ill fisherman also was given timely medical treatment, said Liu Tianrong, deputy director of the South China Sea Fishery Administration under the Ministry of Agriculture.

The 21 fishermen on two boats were caught bomb fishing in China's territorial waters near the Xisha Islands by a Chinese patrol vessel on March 4. They are now being held on Xisha's Yongxing Island.

Bomb fishing, which is illegal, is highly detrimental to fishing resources, said Liu.

China has indisputable sovereignty over the Xisha Islands and their adjacent waters and the detention of the 21 fishermen is in accordance with the law, the official said.

The fishermen were ordered to pay a fine of 70,000 yuan ($11,100) each, he said. Chinese law stipulates that foreigners caught illegally fishing in China's territorial waters could be fined as much as 500,000 yuan.