One person was slightly injured in the attack. The fire was extinguished by the emergency services.
“Everyone at the center has been well cared for and precautions have been taken to strengthen security,” local authorities said in a statement.
The UK’s immigration minister, Robert Jenrick, also commented on the incident.
“My sympathies are with those affected,” he said in a statement.
The port city of Dover is the final destination for many of the migrants who cross the English Channel. So far this year, 40,000 people have arrived in Britain by boat from France.