A Metropolitan Police spokesman added that at this early stage, it is believed the police vehicle had its 'blues and twos' in operation at the time of the collision.
The aftermath of the accident was posted on twitter by several eyewitnesses.
Two people had to be cut out of this car after it crashed with a police van in Bermondsey today. http://t.co/O28MuOrCdd
More top news
Police said they are "extremely concerned" for the welfare of a "vulnerable" mother and her two children who have gone missing in Bexley.
It is hoped the 7,400-mile journey will become a cost-efficient and time-saving way of transporting trade between China and the UK.
The Supreme Court is set to decide on whether disabled travellers are legally entitled to have priority use of wheelchair spaces on buses.