Sat cross-legged on the floor among Shia Muslims observing the sermon was screen legend Morgan Freeman.
Pictures of the Shawshank Redemption actor quickly flooded social media, with celebrity spotters wondering how the A-lister came to be involved in the religious ritual.
It turns out Freeman's appearance at the Al-Khoie Foundation on Tuesday was part of his documentary series
The Story of God, which will explore different cultures and religions to uncover the meaning of life.
Freeman's mosque appearance was not the only head-turning event this Muharram.
In Lebanon, a number of bizarre videos and pictures emerged of a
man dressed as Barney the dinosaur dancing and then falling from a parade float in Dahieh.