DUSHANBE - Construction got underway Monday on the biggest mosque in former Soviet Central Asia, with Tajik President Emomali Rakhmon portraying it as a bulwark against extremism.

Qatar is paying for the mosque that will accommodate up to 150,000 worshippers, state television in Tajikistan reported. Local analysts believe it will cost tens of millions of dollars to build.

"This must be a place that unites people in the service of God and clean ideas, and should not be a platform for non-traditional and alien ideas," said Rakhmon at the televised start of construction.

"It must not become a place for the propaganda of enmity, hatred and extremism with the goal of breaking apart our society."

The mosque - to be dotted with fountains to symbolize Tajikistan's rich water resources - would replace the sprawling and unorthodox Turkmenbashi mosque in neighbouring Turkmenistan as the region's largest.

That mosque, built by eccentric Turkmen dictator Saparmurat Niyazov and plastered with excerpts from his writings, was widely criticized for diverging from Islamic norms.

Rakhmon - who is known to favour lavish construction projects despite his country's poverty - has ordered the closure of dozens of unauthorized mosques in recent years.

Tajikistan fought a civil war in the 1990s against a coalition of Islamists and liberals that left as many as 50,000 people dead and decimated its economy.

Earlier this year government forces battled militants believed to be linked to the Taliban near the Afghan border, sparking fears that the conflict in Afghanistan could spill into Tajikistan.