David Moyes has reportedly been the subject of death threats by Manchester United and Everton fans following his appointment at Old Trafford.

The 50-year-old agreed a six-year contract to join the Red Devils yesterday, a day after Sir Alex Ferguson announced that he will retire after an illustrious 26-year career with the club.

According to the Daily Star, some fans expressed their anger towards Moyes on Twitter following the announcement. One tweet read: "David Moyes I'm warning you...Come to United and f*** us up and I will personally kill your family! That is all."

Another message said: "I'll tell you right now Moyes, if you sell Rooney imma kill yo ass!"

Police are thought to have been monitoring the social networking website last night.