Police and other emergency services are carrying out a search at the River Don in Mexborough, South Yorkshire, for an 11-year-old boy reported missing after being seen entering the water. Multiple reports say the boy was last seen entering the River Don near Ferry Boat Lane and did not reappear. Police were called at about 7.59pm on Saturday following the report. The search is described as ongoing, with responders working to locate the child in the river and surrounding area. News outlets report that the boy has not been seen since Saturday evening, when he was believed to have entered the river. Coverage focuses on the timing and location of the sighting and the fact that the boy was not seen getting out. Some reports refer to wider concerns about water-related incidents, but the shared core information across outlets is the missing child, the reported entry into the River Don near Ferry Boat Lane, and the immediate emergency response that follows the report to police.