Khartoum - A Russian diplomat and his wife were stabbed in Sudan's capital on Tuesday by a man from Central African Republic, Khartoum police said.
The attacker had just heard his brother had been killed by European troops in his home country and wanted to take revenge by attacking a Westerner, the force added in a statement.
Both Russia's consul general and his wife were in a stable condition, the statement added.
Central African Republic, which borders Sudan, descended into chaos in March after a mostly Muslim rebel coalition, Seleka, marched into the capital, unleashing a wave of killings and looting.
Its former colonial ruler France has sent in troops to defend its citizens and back up African peacekeepers trying to contain the violence.
The European Union has also promised to send in soldiers, but Russia has no troops on the ground.
"There was no motive other than revenge for the death of brother," the police statement read.
The duty officer at Russia's embassy in Khartoum said he could not comment and the Russian Foreign Ministry could not immediately be reached for comment.