The European Union has cut off financial support to Niger following last week's military coup attempt, as the African Union called on military leaders to return to their barracks.

The country's elected President Mohamed Bazoum has been held hostage by the military for four days, and Abdourahamane Tchiani, the army general who led the coup in the West African country, has declared himself leader.

On Saturday, the AU issued a 15-day ultimatum to the military leaders in Niger to reinstall the country's elected government. After its meeting, the African Union Peace and Security Council said it was concerned over the alarming resurgence of coups that undermine stability on the continent.

The AU asked the soldiers who staged the rebellion to return immediately and unconditionally to their barracks and restore constitutional authority, within a maximum of 15 days. According to Xinhua News Agency, the United Nations Security Council on Friday strongly condemned Wednesday's military coup in Niger that ousted President Bazoum.

The council members called for the immediate and unconditional release of the president, and underscored the need to protect him, his family and members of his government, according to a press statement cited by Xinhua.

The UN Security Council members expressed concern over the negative impact of unconstitutional changes of government in the region, the increase in terrorist activities and the dire socioeconomic situation.

They also underlined their regret over the developments in Niger, which undermine efforts at consolidating the institutions of governance and peace in that country.

On Saturday, the European Union suspended security cooperation and financial aid to Niger, while the United States threatened to do the same after Nigerien military leaders announced they had overthrown the government.

The AU said it condemns in the strongest terms possible the overthrow of the elected government, and expressed deep concern over the alarming resurgence of military coups in Africa.

Meanwhile, France on Sunday warned it would retaliate if its citizens were attacked in Niger, after protesters tried to enter its embassy in the capital, Niamey, according to Agence France-Presse. France had suspended development aid and budgetary support to Niger.

The recent takeover is the fifth time the military has been successful in seizing power in the West African nation since it gained independence from France in 1960, with other unsuccessful attempts in between.

Tchiani appeared on state television on Friday, appealing for support from the people of Niger and from foreign governments and international partners.

Niger's military leaders warned against any armed intervention in the country as West African leaders gathered in Nigeria's capital Abuja on Sunday for an emergency summit to decide on further actions to pressure the army to restore order, according to Reuters.

In the meeting, heads of state of the 15-member Economic Community of West African States and the eight-member West African Economic and Monetary Union said they could suspend Niger from its institutions, cut off the country from the regional central bank and financial market, and close borders.

Agencies contributed to this story.