Thailand and Malaysia will tighten controls over shipments of poultry across their border in a bid to halt the spread of bird flu. The agreement comes as groups opposed to animal trafficking warn the trade may also lead to the spread of diseases from animals to humans.

Senior agricultural officials from Malaysia and Thailand, meeting in Bangkok Tuesday, agreed to step up efforts to curb the movement of poultry across their border.

Malaysian officials have blamed smuggled Thai fighting cocks for an outbreak of avian flu in Kelantan state.

Officials at the Malaysian Department of Veterinary Services say the problem lies in coordinating efforts to prevent the movement of birds over the border.

Officials from the two countries agreed to set up an early warning system and to immediately share information on outbreaks.

While the H5N1 strain of bird flu has claimed up to 28 lives in Thailand and Vietnam in the past year, no human cases have been found in Malaysia. Humans generally appear to contract the virus from infected birds, but scientists around the world are afraid the H5N1 strain could soon change to become more contagious to humans, leading to a dangerous flu epidemic.

Since the initial outbreak early this year, millions of poultry have been culled throughout Asia to halt the virus. Experts, however, say it could take years to contain the disease.

The concerns come as conservation groups warn that uncontrolled trade in wildlife could spread dangerous diseases to humans.

Steven Galster, executive director of the wildlife protection group WildAid, says increased regional cooperation is necessary to halt the illegal trade. "Better safe than sorry," he noted. "Get a handle on the trade, take a look at what's potentially going to be transferred from animals to people first, and that's not being done. Right now the trade is out of control; the legal trade is huge; the illegal trade is getting bigger."

The H5N1 virus has been found in wild birds, and the SARS virus, which caused more than 800 deaths last year, is thought to be carried by wild animals, such as a weasel-like animal called the civet cat in China. The civet is eaten as a delicacy in southern China.

Mr. Galster said countries needed to link various agencies, such as customs and agricultural ministries to share information across borders about wildlife trafficking.