A total of 139 grave sites of suspected migrants have been found in 28 human-trafficking camps close to the Thai border in north Malaysia, say police.

Police chief Khalid Abu Bakar said the graves had been found since 11 May, and some may contain more than one body.

They are close to where police in Thailand had earlier found trafficking camps and dozens of shallow graves.

Thailand's subsequent crackdown on trafficking has led to thousands of migrants instead leaving by sea.

"[In] The operation which we have been conducting from 11 May to 23 May we discovered 139 of what we believe are graves," Mr Khalid told reporters on Monday.

The grave sites are hundreds of metres from the graves discovered in Thailand, he said.

The graves are evidence of a human trafficking business where migrants are kept in jungle camps while ransom is demanded from family members.

Source: BBC