Sunday's Mediterranean shipwreck in which 700 migrants are feared to have drowned was the latest and deadliest in a series of disasters involving overcrowded boats operated by people smugglers.

The five worst incidents of recent years:

April 19, 2015: An estimated 700 people are feared dead after a crammed fishing boat capsizes in Libyan waters. Only 28 people survive.

April 12, 2015: Up to 400 migrants drown after their vessel capsizes off the Libyan coast. Rescuers save 145 passengers.

February 2015: More than 330 die after being ordered by traffickers to embark from Libya on overcrowded rubber dinghies in atrocious weather. Some 30 rescued alive die of exposure before the Italian coastguard can get them to hospital.

September 2014: An estimated 500 migrants drown off Malta after people smugglers ram their boat in an attempt to force them onto a smaller vessel. The deadliest incident of its kind prior to Sunday's tragedy.

Oct 2013: At least 366 people die when a ship carrying 500 migrants begins to sink and then catches fire just off the Italian island of Lampedusa. Many of the victims are trapped in the hold and asphyxiate. The horrific tragedy puts the issue on front pages around the world and prompts a visit by Pope Francis.