Gen Abdourahmane Tchiani has declared himself the new leader of Niger after a dramatic coup.

Also known as Omar Tchiani, he staged a takeover which started on Wednesday when the presidential guards unit he led seized the country's leader.

This shatters Niger's first peaceful and democratic transition since independence in 1960.

President Mohamed Bazoum is thought to be in good health, and still held captive by his own guards.

He had been considered a key ally by Western nations in the fight against Islamist militants in the region.

The coup has been roundly condemned by international bodies including the African Union, West African regional bloc (Ecowas), the EU and the UN.

However, the leader of Russia's Wagner mercenary group has reportedly praised the coup, describing it as a triumph.

"What happened in Niger is nothing other than the struggle of the people of Niger with their colonisers," Yevgeny Prigozhin was quoted as saying on a Wagner-affiliated Telegram channel.

The BBC has not been able to verify the authenticity of his reported comments.

Gen Tchiani, 62, has been in charge of the presidential guard since 2011 and was promoted to the rank of general in 2018 by former President Mahamadou Issoufou.

He had also been linked to a 2015 coup attempt against the ex-president, but appeared in court to deny it.

Speaking in a televised address, Gen Tchiani said his junta took over because of several problems in Niger, including insecurity, economic woes and corruption, amongst other matters.

Niger's coup is the latest in a wave of takeovers that have hit the West African region in recent years, toppling governments in countries including Mali, Guinea and Burkina Faso.

It also comes as a big blow to the leadership of Ecowas. Just two weeks ago, the bloc's chairman, President Bola Tinubu, warned that terrorism and the emerging pattern of coups in West Africa had reached alarming levels and demanded urgent, concerted actions.

There are now concerns about which countries the new leader will align with. Niger's neighbours, Burkina Faso and Mali, have both pivoted towards Moscow since recent coups of their own.