A jihadist attack on a military camp in western Niger three days ago left 89 soldiers dead, according to a new toll announced by the government on public radio Sunday.
"After a thorough search, the toll has been established as 89 dead among friendly forces, and 77 dead for the enemy," said spokesman Zakaria Abdourahame.
Three days of national mourning have been declared to honour the dead.
The previous toll given for Thursday's attack on the Chinegodar camp was 25 soldiers killed.
Heavily armed assailants had stormed the military base in an area where dozens also died in a previous jihadist attack.
The raid near to the volatile frontier with Mali was carried out by attackers in vehicles and on motorbikes.
The attack happened in the same region Tillaberi, also bordering Burkina Faso, where 71 Niger soldiers were killed in a December attack, claimed by the Islamic State group, that saw hundreds of jihadists storm a camp near the border with Mali with artillery.
The latest attack is the deadliest on Niger's military since Islamist extremist violence began to spill over from neighbouring Mali in 2015.
The December attack spurred leaders of the G5 Sahel nations to call for closer cooperation and international support in the battle against the Islamist threat.
Militant violence has spread across the vast Sahel region, especially in Burkina Faso and Niger, having started when armed Islamists revolted in northern Mali in 2012.
Thousands of civilians have also died and more than a million have been forced to flee their homes since the jihadist revolt began.
Analysts note an escalation in the jihadists' operational tactics, which seem to have become bolder and more complex in recent months.
Ranged against them are the impoverished armies of Chad, Burkina Faso, Mali, Mauritania and Niger, plus a 4 500-man French force in the Sahel and the 13 000-man UN force in Mali, MINUSMA.
The Sahel region of Africa lies to the south of the Sahara Desert and stretches across the breadth of the African continent.