The rebels killed minority Tutsis as well as Hutus they accused of collaborating with the Tutsi-led government in pre-dawn attacks on Tuesday, said Colonel Karenze Karake, deputy commander for the region.
All 14 of those abducted from the neighbouring villages of Ngororero and Nyakabanda, 40 kilometres (25 miles) west of Kigali, were Hutus, he said.
Rebels left a note saying they were abducting one man because he had co-operated with the government.
The army did not know what had happened to the missing people.
On Monday, rebels attacked Kibilira and Muhoruro, 50 kilometres (30 miles) west of Kigali, killing an unknown number of civilians and looting shops, Col Karenze said.
The rebels include members of Rwanda's defeated militia and army, which slaughtered more than 500,000 people, mostly Tutsis and moderate Hutus, in 1994.
The genocide was stopped by Tutsi rebels, who now control the central African country.
AP, KigaliReuse content