Supporters of the coup in Niger have attacked the headquarters of the ousted president's party, attacking politicians and setting the headquarters on fire, stoning and burning cars outside.

In shocking scenes, groups of civilians with some holding Russian flags in beating up politicians who were allies of President Mohamed Bazoum - who was taken captive on Wednesday.

Following the TV announcement on Thursday by some soldiers of a successful coup, Russia joined other countries and the UN in calling for Bazoum's release.

The 64-year-old, who was elected as Niger's president two years ago, is a key Western ally in the fight against Islamist militants in West Africa.

The US and France, who colonized Niger, both have military bases in the uranium-rich country - and have condemned the coup.

US Secretary of State Antony Blinken called Bazoum promising Washington's "unwavering support".

Bazoum took to Twitter on Thursday morning to issue a defiant statement: "The hard-won achievements will be safeguarded. All Nigeriens who love democracy and freedom will see to it."

His foreign minister has also been trying to rally support and urge dialogue, but the army chief of staff said he was backing the takeover to avoid fighting within the armed forces.

In the capital, Niamey, shops and markets opened for business and after delays due to heavy rain early in the morning, coup supporters took to the streets.

The hundreds who gathered outside the National Assembly had some Russian flags, while others held up hand-written signs saying: "Down with France" and "Foreign bases out".

Police later fired tear gas to disperse those who had gone to the headquarters of the ruling party, where party activists ran away when they saw the protesters coming.

The coup supporters accuse the party of corruption and not doing enough to improve the security situation and end the long-running jihadist insurgency.

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