ATHENS — Fires have broken out at a migrants' camp on the Greek island of Samos, leading to its partial evacuation, and firefighters say they are still fighting the flames though they are under control.

A firefighting service spokesman, speaking on condition of anonymity because of an ongoing investigation, said a fire broke out just outside the main camp in an area where there are "shacks" housing some of the overflowing population of migrants as well as medical and other support facilities. The main camp itself is intact, the spokesman added.

There were at least two separate fires, one that started earlier Sunday evening and a bigger one later in the night. The cause is unknown, but local media have reported that the first fire started during a clash between different ethnic groups at the camp and that migrants fueled the later fire in a bid to be taken out of the camp. These reports have not been confirmed.

Non-governmental organization Doctors Without Borders said in a tweet that the earlier fire left about a 100 people without shelter after their tents were burned. It is not known how many other migrants have been left without shelter as the result of the bigger fire, but some have been escorted by police to a square in the nearby town of Vathy.

Firefighters also moved several people out of harm's way, although the spokesman was not able to tell how many and said the investigation of the incidents will be carried out by police. 

Migrants being kept in the overcrowded island camps are increasingly in despair over the conditions and the slow processing of their asylum applications and are eager to move out. Violence, either among migrants or directed at authorities, has flared up.