CAIRO (Reuters) - The Berlin Christmas market attacker pledged his allegiance to Islamic State leader Abu Bakr al-Baghdadi and called for Islamic State supporters to take revenge of "crusaders" bombing Muslims, a video posted on Amaq news agency showed.

"My message to crusaders bombing Muslims everyday... Their blood will not go in vain. We are a nation behind them and will take revenge for them," he said.

"I call on my Muslim brothers everywhere... Those in Europe, kill the crusader pigs, each person to their own ability."

(Reporting by Mohamed El Sherif; Writing by Asma Alsharif; Editing by Louise Ireland)