Malaysia is tightening control at the border and conducting sampling at farms and on wild birds in efforts remain free from the deadly bird flu.

"Our livestock, chickens and ducks are free. We carry out consistent sampling drive at chicken and duck farms nationwide," director-general of the Veterinary Services Department, Dr Hawari Hussein told Bernama.

He said the department was working closely with other agencies to monitor bazaars in the border towns to prevent smuggling.

He also said that tests confirmed that the dead birds found in Perak, Kedah and Perlis recently did not die of bird flu.

"They (the tests) were confirmed negative, even for the weaker strain of bird flu. We are still investigating the actual cause of death," he said.