Three children, aged between 14 and nine, died on Wednesday morning while another one sustained severe injuries after a grenade exploded at a residential home in the rural Sovu Sector of Ngororero District, Western Province.

Police confirmed the incident and said investigations were ongoing to determine the circumstances that led to the blast.

The deceased children were only identified as Masengesho, 14, Uwiringyimana, 12, and Mbabazi, 9, all siblings.

Their younger sister, only identified Mukandayisenga,6, was by press time under intensive medical care at Kabaya Hospital.

The western region Police Spokesperson, Superintendent Emmanuel Hitayezu, said the grenade went off on Wednesday morning.

Police later tweeted that the blast occurred around 8:30am.

"Our officers are investigating the incident,” Supt Hitayezu said.

"Initial investigations indicate that the grenade that exploded was possessed by the victims’ parents in their home,” Police later announced on their tweeter handle.

The father, identified as Alphonse Hunguribwami and a former soldier who served in the army before the 1994 Genocide against the Tutsi, was by press time under police custody, Supt Hitayezu said.

Police had ealier said it was making efforts to establish facts about the incident and the origin of the grenade.

"We are trying to find out whether the grenade had been hidden at their parents’ home or if the children got it from elsewhere and brought it home before it exploded,” Supt Hitayezu said.

The past years have seen a surge in the sale of scrap metals and children are usually among those seen rummaging fields in search of metals.

"The victims might have picked the explosive device unknown to them that it was dangerous. It is one option we are exploring,” he said.

Ngororero is one of the areas which was affected by insurgence after the 1994 Genocide, with remnants of the Interahamwe militia and soldiers of the defeated government conducting military attacks in the late 1990s.

The attacks might have left unexploded devices buried there and this is one of the leads police is exploring.

"We call upon the public to be cautious while handling any metalic objects. Whenever they see an object they suspect, they should immediately alert security organs,” Supt Hitayezu said.

"We also call upon those who might still own fire arms or explosive military devices to hand them over to police,” he added.