The West African country declared a "nationwide curfew" with immediate effect. It said "unidentified individuals" tried to infiltrate an armory but they had been "rebuffed."
Sierra Leone's government said on Sunday that unidentified gunmen attacked a military barracks and tried to break into an armory at the site in the capital, Freetown.
"In the early hours of Sunday, some unidentified individuals attempted to break into the military armory at the Wilberforce barracks. They have been rebuffed," Information Minister Chernor Bah said in the statement.
The government said security forces were again in control of the situation but it nevertheless said it was issuing stay-at-home orders across the country.
"A nationwide curfew has been declared with immediate effect ... We strongly advise citizens to stay indoors," the statement said.
West African regional group ECOWAS condemned what it described as an attempt to "acquire arms and disturb constitutional order" in Sierra Leone.
Tense atmosphere since contested June elections
The government in the English-speaking West African country has been unsettled since the contested re-election of President Julius Maada Bio in June this year.
The All People's Congress (APC) opposition did not accept defeat and international monitors had recommended the detailed publication of results to assuage doubts about the count.
Anti-government protests in August resulted in the deaths of six police officers and at least 21 civilians. Maada Bio had referred to these as an attempt to overthrow the government.
But in October, the main opposition APC and the government signed an accord after talks mediated by West African regional bloc ECOWAS. It agreed to end its boycott and participate in government in exchange for an end to detentions and court cases it said were politically motivated.
President says 'calm has been restored'
Maada Bio issued a statement on social media on Sunday about the attack, saying he was in the Presidential Lodge in Freetown.
He issued few details but claimed that "calm has been restored." He said that a "combined team of our Security Forces continue to root out the remnant of the fleeing renegades," but offered no indication of who they might be.
He said his government remained "resolute in our determination to protect democracy in Sierra Leone."
A series of West African countries have undergone one or even several military coups in recent years, including Mali, Burkina Faso, Niger, and Guinea, which borders Sierra Leone.
msh/wmr (AFP, Reuters)