China on Wednesday demanded the Philippines guarantee the legitimate rights of 12 Chinese fishermen who were handed long prison terms for illegal fishing in the Philippines.

"Since they were caught in the Philippine waters in April last year, China has been urging the Philippine side to deal with the case in a just way according to law, and ensure their legitimate rights and a humanitarian treatment," Foreign Ministry spokeswoman Hua Chunying said in a statement.

A court in Palawan province in the western Philippines on Tuesday convicted the 12 Chinese fishermen of illegal fishing and sentenced the boat captain to 12 years in prison and each crew member to six to 10 years. They were also fined 100,000 U.S. dollars each.

The Chinese fishing boat ran aground in Tubbataha Reef, a UNESCO World Heritage site, off Palawan in April last year after it got lost on the way back to China from Malaysia.

In Wednesday's statement, Hua said that the Chinese Foreign Ministry and the Chinese Embassy, consulates in the Philippines will continue to offer consular assistance to the Chinese nationals.

She also called on Chinese fishermen to respect laws and carry out normal fishing activities.