TALLINN, Estonia—The apparent abduction and detention of an Estonian security officer raised tensions between Estonia and Russia just two days after President Barack Obama came to the country and vowed to defend it as a NATO member.

Estonia's Internal Security Service, known as KAPO, said its officer Eston Kohver was "illegally detained" at gunpoint early Friday while on duty in southeastern Estonia. It said his abductors had come from Russia and had jammed radio communications and used a smoke grenade in the incident....