Two other people who are relatives to the deceased survived the accident with one admitted to Kieni Mission Hospital in critical condition.
Embu East Administration Police Commandant Charles Machinji said two brothers and the woman died on the spot while the other brother died while undergoing treatment at the Kieni Hospital.
Machinji said the six were coming from an entertainment joint at Kathageri around 2am when the driver lost control of the Honda saloon car near a river.
“They were coming from Christmas celebrations at the time of the accident. They were near their home. People went to their rescue immediately,” he stated while adding that the driver could have been drunk and speeding.
He urged drivers to be careful during the festive season and avoid drunk driving to avert accidents.
He said one of the deceased was a doctor at Aga Khan Hospital; another lived in Nairobi while the other two are farmers in Kigumo area.
Sammy Kavangu, a resident and an eyewitness, said the vehicle veered off the road, hit a tree, rolled several times and landed in a river.
He said one of the survivors was thrown out of the car through the windscreen by the impact and was slightly injured.