• Distress call made by cargo ship off the coast of Corfu

• Ship's captain says no assistance needed

• Ship sailing towards Italy

• Up to 600 illegal immigrants reportedly on boarde

•

How many migrants take the world's deadliest route?

• Three migrants stuck in Calais explain how they got there

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21.00 We will close our live coverage there, but Bruno Waterfield and Menelaos Tzafalias in Athens have this full wrap of the day's events:

Italian officials board migrant cargo ship in Mediterranean after reports of gunmen

19.42 Two Italian helicopters have now reached the cargo ship, with three coastguard officials landing from one of the helicopters to assess whether the Moldovan-flagged Blue Sky M was able to navigate safely.

The Italian navy estimates the ship is carrying around 600 migrants.

Officers suspect the ship was abandoned by people smugglers with hundreds of migrants on board, and was advancing towards the coast on autopilot.

19.10 Bruno Waterfield and Menelaos Tzafalias wrap up the latest developments from Athens:

Italian helicopters are trying to intercept a cargo ship believed to be carrying hundreds of migrants earlier feared to have been hijacked by armed men.

Greek coastguards, already immersed in the complicated rescue of hundreds of passengers from a car ferry in the Adriatic, were alerted yesterday morning by a call from the MV Blue Sky M saying there were armed men on board, according to state television.

A rescue helicopter and a naval frigate were scrambled to the ship, off the north-west coast of Corfu, but were unable to get close to the boat before it left Greek waters.

Online tracking sites showed the vessel, which had been travelling northwards along the coast of western Greece heading for Rijeka in Croatia, turning course sharply west in the direction of the heel of Italy.

It is currently 20 miles off Santa Maria di Leuca, on the heel’s tip, and the Italian authorities said they were scrambling two helicopters to investigate. Port officials said the intention was to land on the vessel if necessary.

18.51 Air force spokesman Capt. Stefano Testa said on Tuesday the Moldovan-flagged Blue Sky M ship was about 20 miles (30 kilometers) off Santa Maria di Leuca, on the southernmost tip of the "heel" of boot-shaped Italy.

Port officials in Bari said the teams were landing on the ship as a precaution to see if there were any problems on board and ensure the situation was under control.

18.36 An Italian helicopter was flying to intercept a cargo ship believed to be carrying hundreds of migrants after it left Greek waters and headed towards Italy, according to a statement from the air force.

The Italian airforce said a helicopter had taken off from its base in Gioia del Colle in southern Italy and was carrying coast guard officials.

17.34 Menelaos Tzafalias, in Athens, has this update on the Blue Sky's progress:

The vessel, on its own means, has left Greece's flight information region (F.I.R.), which coincides with Greece's area of responsibility for search and rescue operations.

The three Greek coastguard vessels and a tugboat which had been ordered to the Blue Sky's position were ordered to return to their Corfu base.

The Hellenic Navy's Navarino frigate is patrolling the area and, according to state-run Athens News Agency's 'sources', is discreetly following the Blue Sky's course.

The head of the Othonoi island community told the Athens News Agency earlier today on Tuesday that the Blue Sky was visible from the island and was seen sailing in a south westerly direction as to avoid gale force winds measuring eight on the Beaufort scale, which could explain its earlier change of course.

17.02 From Athens, The Telegraph's Menelaos Tzafalias has just talked to the Corfu coastguard.

They said there are no reports of migrants reaching Corfu or other local island shores.

They confirmed the Blue Sky is no longer in Greek waters.

16.48 (AP) - A cargo ship believed to be carrying hundreds of migrants headed toward Italy on Tuesday, after telling Greek authorities it didn't require any assistance following an emergency call made by a passenger.

16.32

<noframe>Twitter: Piers Scholfield - Coastguard told us Greek frigate captain communicated with <a href="https://twitter.com/search?src=hash&q=%23BlueSkyM" target="_blank">#BlueSkyM</a> who said not in danger - just asked for food supplies.</noframe> <noframe>Twitter: Piers Scholfield - Greek coastguard spokesman tells my colleague the ship Blue Sky M is now under Italian jurisdiction &amp; no one on board is in danger.</noframe>

16.16 Adm. Nikolaos Patrinos, head of the coast guard's security operations, said the passenger's phone call said the ship was eight to 10 miles off Corfu with a large number of migrants.

We are trying to locate it and seeing what we have nearby.

Patrinos said the passenger had also said "that we are without water, food and blankets."

15.50 Elsewhere in Europe, Spanish police have said that more than 100 migrants on Tuesday managed to scale the six-metre fence surrounding the Spanish exclave of Melilla to enter the territory, while around 40 remained perched on the barrier.

Some 200 people tried to storm into the territory that lies in northern Morocco - which together with the nearby exclave of Ceuta have Europe's only land borders with Africa - in the early morning hours, Melilla police said in a statement.

The flow of migrants hoping to reach Europe via Ceuta and Melilla has swelled this year by the conflicts in Syria and Iraq as well as unrest in parts of north Africa, officials say.

The number of undocumented migrants entering Melilla had surged to more than 4,600 in early December, compared with 3,000 for the whole of 2013, Spain's interior minister said on December 10.

15.48 The ship which issued the distress call, the Blue Sky.

15.40 Some sources in Greece have told The Telegraph that they believe the fate of the Blue Sky could mirror that of a ship found off Crete on November 26.

This is how the Greek Reporter covered that story:

Early yesterday morning, the ship was detected at 60-70 nautical miles south-east of Ierapetra on the island of Crete. The first snapshots taken by the Greek authorities clearly showed over 700 illegal immigrants on board, with several armed men among them.

According to military sources, the armed men among the immigrants are the traffickers, but it is not yet clear how strong the group is and what kinds of weapons they hold.

The passengers’ initial demand was to be towed to Spanish shores, but since adverse atmospheric conditions – the north/north-westerly winds of Beaufort force 8 and waves of up to 3 metres – made this impossible, they agreed to be towed to Crete. Sizeable Greek Navy forces have been concentrated in the waters around Ierapetra.

15.29 This update is just in from the Telegraph’s Menelaos Tzafalias in Athens

Around four hours ago, a call from on board the Moldovan flagged ship Blue Sky was made to the Europe-wide 112 emergency telephone number and the person making the call (whose identity is unknown) said that there were 700 migrants on board the ship and that the also were armed people.

Greek government sources said that the ship is currently north of the island of Corfu about 3.5 nautical miles west of Othonoi island, meaning it is still in Greek territorial waters. Greek authorities still are investigating the incident.

Greek officials have noted that in a recent case where a ship carrying migrants was rescued south of the island if Crete, a similar call was made but it proved there were no armed men on board that ship and that the number of migrants turned out to be much fewer than initially reported.

15.04 Confusing reports about what is going on with Blue Sky MV.

Has it been commandeered? Or is it suffering from technical difficulties? And are there hundreds of migrants on board?

The Greek authorities evidently think it's significant, as they are marshalling their special forces.

15.03

<noframe>Twitter: Military Studies - UPDATE: <a href="https://twitter.com/search?src=hash&q=%23Greece" target="_blank">#Greece</a>'s media is reporting that an overflying HN S-70 Agean Hawk says the ship looks empty. <a href="https://twitter.com/search?src=hash&q=%23BlueSkyM" target="_blank">#BlueSkyM</a></noframe>

15.02

<noframe>Twitter: Yannis Koutsomitis - <a href="http://www.twitter.com/ArmedResearch" target="_blank">@ArmedResearch</a> &Alpha;s of 1400 GMT, a <a href="http://www.twitter.com/HCoastGuard" target="_blank">@HCoastGuard</a> heli was trying to reach the vessel but weather is xtremely bad. Navy frigate headed there</noframe>

14.47 This is interesting.

A Berlin TV channel is claiming that the ship had engine trouble, which is why it issued the distress signal - not because of armed men.

We'll bring you more information as we get it.

<noframe>Twitter: Ruptly Newsroom - UPDATE: Migrant boat stranded off coast of <a href="https://twitter.com/search?src=hash&q=%23Corfu" target="_blank">#Corfu</a> after engine failure, according to reports 600 are on board - our producer is on his way</noframe>

14.37 The vessel which issued the distress call is the BLUE SKY MV, sailing under the Moldovan flag.

Its official destination was Rijeka, Croatia

14.26 You can read the latest on the Norman Atlantic disaster, in which 12 people died and 43 remain missing.

Italy ferry: 'Up to 43 still missing' amid confusion over Norman Atlantic passenger list

14.07 This map shows where the current location of the Blue Sky, and also where the Norman Atlantic - which caught fire on Sunday - was located.

The two areas are just off Corfu.

13.57 Roy Paul, programme director at the Maritime Piracy Humanitarian Response Centre, told Channel 4 News that this was unlike any case he has heard of and could be a hijacking.

This is totally different scenario. Usually we deal with cases off the coast of Somalia to hold for ransom. This is in European waters. It's totally different. Our concern would be for the crew of the vessel.

If they want to take it to the Italian coast, one would assume the Italian navy would try to intercept them. Perhaps on board the ship there were illegal immigrants who may have taken control of the vessel.

He said it was unlikely to be a case of ransoming the ship.

Where is the financial gain? No-one’s going to pay ransom for illegal immigrants.

13.54 The Greek frigate Navarino, which is heading to locate the cargo ship, had been in the area assisting in the rescue operation for the Norman Atlantic.

13.36 This map shows how the Blue Sky made a sharp change in direction.

13.35 The Greek Merchant Marine Ministry said that it was informed of the distress call, which was made over a European frequency, 3.5 nautical miles off the islet of Othoni, by Italian authorities.

The Italians said there may be as many as 400 people on board the vessel.

13.34 The ship was reportedly heading to Croatia.

13.17 Our correspondent Raziye Akkoc has been looking into statistics on migration.

UN data shows more migrants died this year than in the last three years added together crossing the Mediterranean Sea - as the International Organisation for Migration says 2014 was the deadliest year for migrants.

How many migrants take the world's deadliest route?

13.15 More detail on the Blue Sky - the ship which sent out the distress call.

IMO: 7510690

MMSI: 214180618

Call Sign: ERFR

Flag: Moldova (MD)

AIS Type: Cargo

Gross Tonnage: 2240

Deadweight: 3460 t

Length × Breadth: 81.39m × 13.44m

Year Built: 1976

Status: Active

12.58 It's exceptionally unusual for illegal immigrants to commandeer a ship - if indeed this is what has happened.

Migrants normally pass into Europe on foot, through Turkey into Greece, or by boat into Italy.

The seizing of a ship is unheard of.

You can read more about migrant routes into Europe here:

Desperate to reach Britain: three migrants stuck in Calais explain how they got there

12.55 Our correspondent in Athens, Bruno Waterfield, sends the following summary:

Two coastguard boats, naval frigate and helicopter en route

Distress call made on mobile phone on 112 number - cargo ship, Moldava flagged.

This is a bit unusual, not made on ship's radio, nothing confirms yet

Reports of 600 illegal immigrants and 12 man crew

Call made of "suspicions of armed men on aboard", nothing confirmed

12.51 Greece's SKAI television said as many as 700 people may be on board but other reports put the total at 400.

12.42 More from Associated Press:

Greece is sending a navy frigate and a helicopter to locate a cargo ship believed to be carrying hundreds of migrants in the northern Ionian Sea after authorities received a distress call from someone on board the ship, authorities said.

The ship, the Moldovan-flagged Blue Sky M, was sailing in poor weather near the tiny island of Othonoi, northwest of Corfu. Authorities said the distress call had come from one of the passengers on board the ship.

The ship is believed to be carrying about 600 migrants.

The incident comes two days after a Greek passenger ferry with more than 400 people on board caught fire in the same area, leading to a huge rescue operation by Italian and Greek coast guard and military officials. At least 10 people died in that incident, while more than 400 were rescued.

Authorities are searching for potential missing passengers from the Norman Atlantic ferry.

The Greek frigate Navarino, which is heading to locate the cargo ship, had been in the area assisting in the rescue operation for the Norman Atlantic.

12.32 Initial reports suggested it was a passenger ship - this now appears not to be the case.

12.31 This is the latest news from Reuters:

A vessel that called for help off Greece is a Moldovan-flagged cargo ship believed to be carrying migrants, Greece's shipping ministry said on Tuesday.

Greek state television earlier reported a passenger ship issued a distress signal because of armed people on board.

The "Blue Sky M" was sailing off the island of Corfu, a shipping ministry spokesman said. The vessel was carrying hundreds of migrants, Greek television stations reported.