Russia and Algeria drew 1-1 in their final Group H game with the African side advancing at the expense of Capello's team. (Agencies)
Russian goalkeeper Igor Akinfeev failed to reach a cross which was headed home by Islam Slimani in the 60th minute to earn Algeria a point.
Television images showed what appeared to be green laser beams flashing across the keeper's body as he tried to reach the cross.
"Our goalkeeper was affected by a laser 10 seconds before the goal. He was blinded by a laser, there are photos, films of it," Capello said.
"I'm not looking for excuses. I accept defeats," added the Italian.
Akinfeev made a blunder in the opening Group H game against South Korea, letting in a shot from Lee Keun-ho to allow the Asian side take the lead in the 1-1 draw.
Use of lasers by fans is an increasingly common problem in North African football.
Last year, the second leg of the African Champions League final in Cairo between Egypt's Al-Ahly and South Africa's Orlando Pirates was badly affected by green lasers beamed into players’ faces.
Russia and Algeria drew 1-1 in their final Group H game with the African side advancing at the expense of Capello's team.