By Paul Anderson
BBC News, Quetta
Leading religious scholars in Pakistan have decreed that the use of heroin is un-Islamic, in a move designed to curb a surge in the drug's popularity.
A bumper poppy harvest has been blamed for rising heroin use
The decree, or fatwa, was issued at a seminar in the western province of Baluchistan, next to Afghanistan.
The seminar brought together Islamic scholars and officers from the military's anti-narcotics force.
Pakistan is gripped by an unprecedented heroin and opium crisis - a product of the poppy boom in Afghanistan.
Resources to tackle the smugglers and rehabilitate the users are thinly stretched.
Baluchistan, with its vast wilderness of unpoliceable mountains and deserts, faces the greatest threat from the smuggling and consumption of opium and heroin from neighbouring Afghanistan.
The seminar in Quetta saw Pakistan's military Anti-Narcotics Force (ANF) teaming up with some of the country's foremost Islamic scholars and preachers.
The idea behind the seminar was to use their reach and influence to convey the message that the cultivation and use of drugs go against the Koran.
Among those attending were 40 mufti - or scholars entitled to issue fatwas - from all districts of Baluchistan.
The seminar followed a statement from a lesser religious leader some time ago that some cultivation of poppy - the base crop for opium and heroin - was permissible for medicinal purposes.
One of Pakistan's leading Islamic scholars, Professor Anis Ahmad, dismissed this as a complete misapprehension.
"The scholars all over the ages are unanimous that things which envelop our reason, which cause illusions and hallucinations, all those drugs and chemicals which lead to a life which is not real, these are prohibited," he said.
Most of the heroin which ends up in Western European markets is smuggled through Pakistan.
Much spills off the trafficking routes for local use.
Pakistan currently has about half-a-million heroin addicts.