Syria on Monday denied a report that President Bashar al-Assad's regime is building a secret underground plant with the aim of developing nuclear weapons, state news agency SANA said.

"Syria denies these allegations," said SANA.

It accused German news magazine Der Spiegel of publishing "lies and ridiculous allegations, like the idea that Syria is building a nuclear plant."

Citing information made available by unidentified intelligence sources, Der Spiegel last week said the plant was in an inaccessible mountain region in the heart of the war-ravaged country, near the town of Qusayr.

The Lebanese militia Hezbollah, which supports Assad's regime in the bloody conflict in Syria, is guarding the secret project, Der Spiegel added.