ATHENS (Reuters) - Two migrants were killed and two others were injured in a fire at a migrant camp on the Greek island of Lesbos late on Thursday, prompting clashes between other migrants and the police, authorities said on Friday.

The fire broke out at 2020 GMT after a gas canister used for cooking exploded in a tent in the camp of Moria. A woman, 66, and a 6-year-old child were killed, police said, and another woman, 25, and a 4-year-old child were seriously injured and transferred to Athens.

After the fire, dozens of frustrated migrants fought briefly with police. Many people evacuated the center and camped under trees.

“We are not animals, we are human beings,” a migrant told reporters. “You people say United Nations, United Nations has human rights but we don’t see any human rights here. We don’t see any freedom, we don’t see any democracy here.”

Video footage showed tents in flames and migrants searching through debris. Dozens of tents were burned and container cabins with medical supplies, clothes and documents were damaged, a police official said.

Police and the fire brigade were investigating the incident. The fire was contained early in the morning.

More than 6,000 migrants and refugees are stranded on Lesbos, an island close to the western coast of Turkey. Their total is twice the capacity of the government-run camp of Moria and a center administered by the municipality.

Tensions have boiled over at overcrowded camps in the Greece, which is struggling to emerge from a debt crisis, as the slow processing of asylum requests adds to frustration over living conditions.

Migration Minister Yannis Mouzalas told parliament the government would start transferring migrants to the mainland soon to reduce overcrowding at island camps and urged residents to cooperate with the state and help to ease tensions.

Under a European Union deal with Turkey, migrants and refugees arriving after March 20 are to be held in centers set up on five Aegean islands, including Lesbos, and sent back if their asylum applications are not accepted.

Referring to the incident and the management of the migrant crisis, Prime Minister Alexis Tsipras said the government “was fighting a battle in adverse conditions”.

“I’m shocked by the tragic event in Moria,” he said in a statement. “The Greek government will further intensify efforts for safety and a better quality of life in reception centers.”