Criminal gangs are selling more cheap and easy-to-make amphetamine-type drugs, such as ecstasy and crystal meth, in new markets, and cannabis is now the only more widely used illegal drug, a United Nations report released on Tuesday said.

The number of methamphetamine pills seized in southeast Asia, for instance, nearly tripled in a year to 93 million in 2009 and then rose to 133 million in 2010, the study said. The number of ATS laboratories raided there also soared.

Police seizures of all amphetamine-type stimulants (ATS) rose between 2005 and 2009—except ecstasy, which remained constant—while heroin, cocaine and cannabis held largely stable, according to the U.N. Office on Drugs and Crime (UNDOC).

"The ATS market has evolved from a cottage-type industry typified by small-scale manufacturing operations to more of a cocaine or heroin-type market with a higher level of integration and organized crime groups involved throughout the production and supply chain," said UNODC Executive Director Yury Fedotov.

Several European countries have reported an increase in the use and production of methamphetamine, which is stronger and acts faster than standard amphetamines.

West African countries have started to manufacture the drugs, it said, noting ATS seized in several East Asian countries appear to have originated in West Africa.

Central and South American countries are reporting a rise in ATS manufacturing with laboratories dismantled in Brazil, Guatemala and Nicaragua, the UNDOC report said.

It also highlighted the emergence of new stimulants called analog substances, which fall outside international controls and are widely available on the Internet.

Drugs such as mephedrone or methylenedioxypyrovalerone that were first surfaced last year are sold as "bath salts" or "plant food" and substitute for illegal drugs such as cocaine, it said.

The spreading intravenous use of ATS poses health issues particularly relating to the spread of HIV and AIDS, it noted, citing special concern about this in eastern and southeastern Asia as well as parts of Europe.