At least 21 Palestinians, including 10 children, have been killed by a fire in a building in a densely populated refugee camp in the Gaza Strip, a coastal enclave that has been under Israeli blockade for over a decade.

The number of deaths at Jabalia refugee camp following the fire is likely to rise, medics told PRC. An initial investigation suggested there was a gas leak from a kitchen.

Dr Abu Laila, director of emergency services at the Indonesian Hospital in north Gaza, described the fire as "huge", with videos on social media showing the entire building engulfed in flames.

People were seen screaming outside the burning building, while relatives of victims were in the streets crying and praying.

One local resident who rushed to the scene said that gasoline was stored in the building to "operate a generator".

An eyewitness told the BBC: "It is very difficult, children and women burning without the possibility of saving them."

Deadly fires - often caused by candles - have become a regular occurrence in Gaza because of severe power shortages. These are linked to the blockade imposed on the territory by Israel and Egypt.

Gaza is home to 2.3 million people, one of the highest population densities in the world. According to the UN, almost 600,000 refugees in Gaza are living in eight crowded camps.

Jabalia is the largest of the Gaza Strip's eight refugee camps. It is located north of Gaza City, close to a village of the same name. After the Arab-Israeli war in 1948, 35,000 refugees settled in the camp, most having fled from villages in southern Palestine. Today, the camp covers an area of only 1.4 square kilometres.

The blockade on Gaza has made life increasingly difficult for nearly all refugees in the camp. Unemployment levels have risen dramatically, and fewer families can provide for themselves. Over the years, a staggering proportion of the population, who used to be largely self-sufficient, has become dependent on UNRWA food assistance to cover their basic food needs.

Basic hygiene is also of great concern in the camp with 90 per cent of the water being unfit for human consumption.

Overcrowding and a lack of living space characterize Jabalia camp. Shelters are built in close vicinity and there is a general lack of recreational and social space. In many cases, residents have had to add extra floors to their shelters to accommodate their families, in some cases without proper design. Many live in substandard conditions.