As many as 700 people are missing following a deadly week in the Mediterranean.

The United Nations refugee agency, the UNHCR, says there were three incidents on Wednesday, Thursday and Friday of last week.

Some 100 people died on Wednesday after a boat capsized, while a small boat with no engine began to take on water after it was cut loose from a fishing vessel that was towing it on Thursday.

About 550 people that were on the smaller boat are missing and presumed drowned.

While an unspecified number of people are missing after another rescue operation on Friday.

It says that as many as 40,000 people have tired to cross the Mediterranean into mainland Europe so far this year.

This comes as there are growing fears that increasing numbers of migrants are travelling by small boats in an attempt to illegally reach the UK.

The French coastguard has said that tragedies like those seen in the Mediterranean could soon be seen in the English Channel.

On Sunday, 18 Albanians and two Britons had to be rescued after getting into difficulties off the coast of Kent.

Last month, the deputy director of UK border policing command for the National Crime Agency said that gangs are being paid as much as stg£12,000 (€15,797) to smuggle people into the UK on inflatable boats.

Traffickers are thought to be turning to small boats because authorities are preventing migrants travelling on ferries in vehicles or through the Channel Tunnel.

In the latest incident, two boats suspected of being linked to people smuggling were found on Dymchurch beach.

"It's a sea filled with danger"

President of the French coastguard, Bernard Barron, said the suspected smuggler craft found in Dymchurch was unsuitable for crossing the Channel.

He said: "It's starting to become a very similar situation to that seen in the Mediterranean and my biggest fear is that the same kind of tragedies we see in Greece or Italy will start to repeat in the Channel".

"They operate across the length of both the French and Belgian coastlines, between Ostend and into Normandy, finding new positions from where they can send their clients - the migrants - towards England".

"These smugglers - despite being given large sums of money - provide methods of transport for the migrants that are not suitable for crossing a sea like the English Channel".

"It's a sea filled with danger, with strong currents, storms and heavy traffic of larger vessels".

On Tuesday, another 17 suspected Albanians, and a British man wanted on suspicion of murder in Spain, were detained after a catamaran arrived at Chichester Marina in West Sussex on Tuesday.

They have been detained while the UK Home Office considers their cases.

Two weeks ago, Yachting and Boat World reported that French police had arrested five people in the port of Saint-Quay-Portrieux, Brittany, after finding migrants stowed away on a yacht heading for the UK.

In February, four Iranians were rescued after leaving on an inflatable craft from Dunkirk.

While, last month, two Iranian men were found floating a mile from Dover in an ill-equipped dinghy in the English Channel.

Thousands of migrants have died trying to cross from north Africa to Europe and also from Turkey to Greece, with the UN saying that more than 700 may have drowned in just the last few days.

Jody Clarke is spokesperson for the UNHCR. He told Newstalk Breakfast it has been a tragic seven days at sea.