By Jonathan Head
BBC correspondent in Bangkok
Diplomats in Thailand say there is growing international concern over the rising death toll since the government announced an all-out campaign against drug dealers at the beginning of this month
Thai police are accused of operating outside the law
It has been three weeks since Prime Minister Thaksin Shinawatra vowed to stamp out drugs in Thailand, and the killing seems to be getting out of hand.
Every day newspapers and television programmes show grisly pictures of alleged drug dealers lying in pools of blood, all with guns and bags of methamphetamine pills in their hands.
Official figures put the death toll at more than 600, although the police say that only 300 of these were on an official black list and that nearly all were killed by their rivals.
But the striking similarity among the victims- all shot execution-style- and the fact that no investigations of their deaths have taken place, has led many Thais to suspect that there is an official shoot-to-kill policy in place.
Several ministers have suggested that drug dealers should be wiped out, and local police forces are under strong pressure to show quick results in the fight against drugs.
International human rights organisations have already expressed their deep concern over the killings, which they say have cast a shadow over Thailand's relatively favourable human rights record.