The charity was called yesterday (Thursday) following reports of a spill in the river at Hartford Marina, with birds reported to have been affected by the incident.The Environment Agency was also called to the incident. A spokesman for the RSPCA said: RSPCA officers were called by the Environment Agency to help catch a number of wild birds who had been covered in oil following some kind of spillage into the water. Four officers from the RSPCA attended the location which was near to the Hartford Marina on the River Ouse. So far six swans which had been oiled have been caught, but further rescues are taking place to catch more birds at the location. Officers plan to return back tomorrow as well. The birds will be taken to an RSPCA wildlife centre to be washed and treated. A spokesman for the Environment Agency said: Due to an ongoing significant pollution incident emanating from Huntingdon Riverside Park it is necessary to issue this emergency closure notice for the locks to contain control; and clean up this pollution spill incident. It will be necessary to deploy booms and spill kits on the river and the river will be closed at points within these reaches. Please do not enter this section of river at present and if you are already within this zone of river please moor up at the nearest available moorings until further advice is issued. At present we do not advise navigating within this zone and through any areas of pollution. We are also advising people to keep off and out of the river and not to allow their pets into the water at the current time. Teams are mobilised and working with partners in relation to this incident and we will issue a further update when more information becomes available. We have been monitoring the river pollution from Huntingdon Riverside Park. The oily substance has been captured within booms placed in the river and contained until it can safely be removed. The locks will be open to navigation later this afternoon (Friday). We are continuing investigations to allow us to accurately identify the substance and how it was able to reach the river. We are aware of various reports via social media. If anyone has any information we would ask them to report it to our incident hotline number 0800 807060.