Soldiers in Niger claimed to have removed President Mohamed Bazoum from power late on Wednesday, hours after members of the presidential guard detained the politician at his official residence.

In a statement broadcast on national television, Colonel-Major Amadou Abdramane said “the defiance and security forces … have decided to put an end to the regime you are familiar with”.

“This follows the continuous deterioration of the security situation, the bad social and economic management.”

The soldier said the country’s borders were closed and declared a nationwide curfew. All institutions of the country were also suspended, he added.

Abdramane was seated and flanked by nine other officers wearing fatigues as he read out his statement. The group, which is calling itself National Council for the Safeguarding of the Country, warned against any foreign intervention.

The announcement came after a day of uncertainty as members of Niger’s presidential guard held Bazoum after surrounding the presidential palace. It was unclear where the president was at the time of the announcement or if he had resigned.

The United States immediately called for Bazoum’s release. “I spoke with President Bazoum earlier this morning and made clear that the United States resolutely supports him as the democratically elected president of Niger,” US Secretary of State Antony Blinken told reporters in New Zealand. “We call for his immediate release,” he added.

Earlier on Wednesday, a tweet from the account of Niger’s presidency reported that members of the elite guard unit engaged in an “anti-Republican demonstration” and unsuccessfully tried to obtain support from other security forces.

It said Bazoum and his family were doing well but that Niger’s army and national guard “are ready to attack” if those involved in the action did not back down.