Mapping Mediterranean migration
The deaths of around 300 migrants off the small island of Lampedusa on 3 October has brought the issue of migration in the Mediterranean sharply back into focus.
Every year thousands of people, many fleeing conflict and instability in Africa and the Middle East, risk their lives in small, often decrepit vessels while trying to cross the Mediterranean Sea to European territories.Continue reading the main story
Then, on 11 October, more than 30 people died when another boat packed with around 250 people sank just off the coast of Malta.
Some 200 people were rescued, and Malta's prime minister warned that the Mediterranean was in danger of becoming of a "cemetery" for desperate migrants.
The UN says some 32,000 people have arrived in Malta and Italy so far this year.
At the weekend more than 200 migrants also arrived in Sicily after being rescued by the Italian coastguard and a merchant ship.
Migrants crossing in the central Mediterranean - from Libya and Tunisia - come mostly from Eritrea and Somalia, although increasing numbers of Syrians fleeing the country's civil war are also making the journey.
Speaking to reporters, the UNHCR's Adrian Edwards said: "The phenomenon of people travelling on small boats across the Mediterranean to Europe is age-old and involves issues of asylum as well as migration.
"Those on board the boat that sank off Lampedusa were nearly all Eritrean, and many are likely to have been in need of international protection."
Migration charities believe that as many as 20,000 people may have died at sea trying to reach Europe in the last two decades.
The i-Map project was developed as a joint initiative by European border management agency Frontex and the International Centre for Migration Policy Development, and produces detailed maps showing the routes and major hubs used by migrants in the region.
Libya has become a popular starting point for many journeys, with people traffickers exploiting the country's power vacuum and increasing lawlessness.
The relatively short distance between Libya and the Italian island of Lampedusa encourages more people to risk the journey.
The number of people using the various routes across the Mediterranean has ebbed and flowed.
From 2008-2012, large numbers of migrants crossed between Turkey and Greece via the so-called Eastern Mediterranean route, border management agency Frontex reports.
In response, Greece bolstered border controls with an additional 1,800 police officers.
However, Frontex suggests that the area remains problematic, and points to "uncertainties related to the sustainability of [Greek] efforts, and evidence that migrants are waiting in Turkey for the end of the operation".
Over the last decade, the central Mediterranean route has experienced periodic surges in migrant traffic.
UNHCR figures suggest that some 25,000 people fled to Italy from North Africa in 2005, a number which dwindled to 9,573 in 2009.
In 2011, this figure rocketed back to some 61,000, driven by the conflict in Libya which culminated in the downfall of Col Gaddafi.
Earlier in the decade, the most popular route was from West Africa to Spain, including its North African territories of Ceuta and Melilla, and the Canary Islands, with some 32,000 irregular arrivals in 2006. This figure had dwindled to just 5,443 by 2011.