The injured are admitted at Longisa Mission Hospital.
The government has intensified its operation to restore calm in clash-torn Narok South even as a 13-year-old boy was hacked to death on Monday morning.
Narok County Commissioner George Natembeya said more security officers have been sent to the area.
"I want to assure the public that police are alert. They are ready to deal with any violence," Mr Natembeya said, adding that the attack was not related to the clashes.
The skirmishes erupted three days ago when a herder was killed in Nkoben, Maasai Mau forest. According to police, more than 58 houses have been burnt so far.
Mr Natembeya and regional police bosses flew to Mau forest in the evening to help in the search for stolen animals.
The child was hacked to death at the family home in Esimendwa village. His 12-year-old Standard Six sister and grandmother, identified as Esther Maina, 73, sustained deep panga wounds. A three-year-old survived by hiding under the a bed.
The victims were taken to Longisa Hospital before being transferred to Tenwek Mission Hospital. Relatives told the Nation that the children, whose mother died two years ago, were living with their grandmother.
“The attackers stormed the homestead around 2am. We only found out in the morning,” Mr Hosea Bungei, a neighbour, said.
Ms Emily Kirorei, another neighbour, said the children's father was not at home. “Attacking innocent and helpless children and women invites a curse,” Ms Kirorei said.
Mr Natembeya said out of the 15 schools affected by the clashes, seven opened on Monday.
More than 35 people have been injured, 29 others arrested and hundreds of families have fled since the clashes began. The skirmishes spread to Olollipang’ai, Ereteti, Enakishomi and Olmekenyu villages.
Meanwhile, former Bomet Governor Isaac Ruto, Chepalungu MP Gideon Koskei and seven ward representatives asked the government to arrest perpetrators and inciters of the clashes.
"That Education Cabinet Secretary Amina Mohamed has not addressed the plight of Standard Eight and Form Four candidates in the 30 schools affected by the clashes and forest evictions is disheartening," Mr Ruto said at a press conference in Bomet town.
The leaders told the Directorate of Criminal Investigations, the National Cohesion and Integration Commission and the Director of Public Prosecutions “to take action against violence instigators hiding behind cattle rustling”.
"Those who attacked a family in Esimendwa village are criminals who should be dealt with according to the law. The attack happened at a time of relative calm," the former Bomet County boss said.
He asked Environment Cabinet Secretary Mr Keriako Tobiko to tread with caution when evicting families from the forest.
Mr Koskei asked the government to address the factors behind the clashes.
“The smokescreen is cattle rustling, which is an age old practice between the two communities," the Chepalungu MP said.
Calm returned when the government dispatched more than 300 police officers to the area following the clashes that have so far claimed five lives.
The villages affected are Olmekenyu, Oloisisho, Ololoipangi and Naiurur. Ololiserr, Entere, Esimendwa and Nadupa Primary schools in Ololunga division remain closed.