The UN has called for the immediate transfer of migrants from an overcrowded Greek refugee camp on the island of Lesbos after a deadly fire at the camp there sparked riots.

Camp residents say a woman and child died in yesterday's blaze at Moria, Europe's largest migrant camp, which houses around 13,000 people but has facilities for just 3,000.

The civil protection ministry has confirmed the death of one person and said they were carrying out tests on the remains of a possible second victim.

Late Sunday, Greek news agency ANA had cited police sources as saying a mother and child had died.

A plane helped extinguish the fire that had spread to several containers housing migrants.

Police later fired tear gas to control an angry crowd who said authorities took too long to respond to the incident.

The UN's refugee agency has warned the situation at Moria was "critical" and required "urgent" action.

"We are calling to accelerate the transfers and improve conditions in Moria," said Boris Cheshirkov, UNHCR's spokesman in Greece.

Lesbos mayor Stratos Kytelis also called for the "immediate decongestion of our islands and for borders to be guarded".

The camp has become like a small town with UN refugee agency tents for around 8,000 people sprawling into the olive fields of nearby Moria village. Others are housed in containers.

The situation was calm at the camp today but there was still a strong police presence, the UNHCR and migrants said.

Some 247 migrant were to be transferred from Lesbos to the Greek mainland today, the UNHCR said.

The Deputy Minister of Citizen Protection, Lefteris Economou, along with the Chief of Police and the Secretary General for Migration Policy, were due to visit Moria today.

Greece hosts some 70,000 mostly Syrian refugees and migrants who have fled their countries since 2015, crossing over from neighbouring Turkey.

Under an agreement reached with the European Union in 2016, Turkey has made greater efforts to limit departures towards the five Greek islands closest to its shores.

However the number of arrivals has been steadily climbing in recent months causing a dangerous burden in the camps of the islands that are in the forefront of the migrant influx.

The Greek government said yesterday it planned to discuss a new asylum draft law to deal with the fresh migrant crisis.