Barack Obama has celebrated winning another term as US president by tweeting a photograph of himself hugging his wife, Michelle – which almost immediately became the most popular tweet of all time.
The tweet, captioned "Four more years", had been shared more than 400,000 times within a few hours of being posted, and marked as a favourite by more than 70,000.
Another tweet, sent from his account shortly earlier, was close behind with almost 200,000 retweets. In it he thanked his supporters, writing: "This happened because of you. Thank you."