Migrant boat tragedy: Three days of mourning announced in Greece

Greece has declared three days of national mourning after a fishing boat sank off its southern coast.

No one's quite sure how many people were on the ship, but some people on board have reported it could have been as many as 750, with 100 of those being children.

The United Nation's International Organisation for Migration has said the number is closer to 400.

Officials have confirmed that many people have died, but more than 100 people have been rescued.

Some survivors are being treated in hospital in the Greek city of Kalamata.

The boat is thought to have been travelling from Libya to Italy.

It ran into trouble when its engine stopped working around 80 km (50 miles) south-west of the Greek town Pylos.

It then capsized and sank just after 2am on Wednesday, in what one of the coastguards described as one of the deepest parts of the Mediterranean ocean.

The coastguard said they couldn't see anyone on board wearing life jackets.

Officials have said they expect the search and rescue operation to last until at least Friday.

Greek President Katerina Sakellaropoulou visited some of the survivors and expressed her sorrow at the tragedy.

Some people are saying that the Greek authorities did not act quickly enough to help the boat and people on board but they say their offers of help were refused.

Boat journeys like these are becoming increasingly common.

Many people are leaving their home countries because it's not safe to live there, often because of war or because they are being persecuted for their beliefs.

Some may want to find a new place to live for a better life.

People that move countries for any reason are called migrants. If someone is running away from a country because their lives are in danger there, they're known as refugees.

Often they want to come to European countries or the UK.

More than 70,000 refugees and migrants have arrived in European countries this year, with most travelling to Italy, according to United Nations data.