Niger's ousted leader has urged the US and "entire international community" to help "restore... constitutional order" after last week's coup.

In an opinion piece in the Washington Post, President Mohamed Bazoum said he was writing "as a hostage".

Unrest has erupted in the West African state since he was overthrown.

On Thursday, the coup leaders announced they were withdrawing the country's ambassadors from France, the US, Nigeria and Togo.

In a statement read out on national television, they said the functions of the four ambassadors had been "terminated".

Niger is a significant uranium producer and lies on a key migration route to North Africa and the Mediterranean.

In his newspaper article, Mr Bazoum warned the coup, if it succeeded, would have "devastating consequences for our country, our region and the entire world".

"Fighting for our shared values, including democratic pluralism and respect for the rule of law, is the only way to make sustainable progress against poverty and terrorism," Mr Bazoum wrote.

"The Nigerien people will never forget your support at this pivotal moment in our history."

On Thursday, thousands of people took to the streets of Niger's capital, Niamey, in a peaceful demonstration in support of the coup.

They condemned other West African countries in the regional trade bloc, the Economic Community of West African States, for imposing financial and trade sanctions on Niger.

Mr Bazoum, the first democratically elected president to succeed another in Niger, was detained by his own guards last week. Coup leader Gen Abdourahmane Tchiani has been installed as head of state.

Niger is a key part of the African region known as the Sahel, an area plagued by jihadists and beset by military regimes. In recent years it had been seen as an example of relative stability, while its neighbours Mali and Burkina Faso succumbed to military coups.