A teenage boy has been found clinging to the underside of a coach full of British tourists in Spain after surviving a 155 mile journey from North Africa.

The young migrant, believed to be 15, had apparently crammed himself into a cavity underneath the bus as it travelled through Morocco, on a ferry and across mainland Spain to Seville.

Local reports said he was discovered after it parked outside a hotel and tourists heard his cries.

A spokesperson for Seville’s emergency services said the coach had travelled 155 miles.

“Police and firelighters have rescued a minor on the underside of a bus coming from Tangier," he added.

“He was transferred in good condition to a hospital in the city.”

Footage showed the boy, appearing extremely thin and covered in dirt, being taken for medical treatment in an ambulance after being led from the coach.

Officials checked for more stowaways but none were found, and the boy is expected to be taken to a holding centre for irregular migrants as a police investigation continues.

The coach was operated by a British travel company that offers tours of Spain, Morocco and Portugal, taking around six hours to travel from the North African coast to Seville.

An itinerary published online includes a journey through the cities of Fez, Marrakesh, Casablanca, Rabat and Tangier to Seville, via a ferry over the Strait of Gibraltar to the Spanish mainland.

Migrants being held by police at the Ceti detention centre in Ceuta after crossing the border from Morocco to the Spanish enclave on 17 February (Reuters)

It is the first reported case of a migrant crossing from Morocco to Spain by hiding in a vehicle, which is frequently a tactic used by asylum seekers attempting to reach the UK from Calais.

Thousands of asylum seekers have reached Spain either by crossing the Mediterranean Sea in overcrowded boats or attempting to scale the 20ft defences surrounding the Spanish enclaves of Ceuta and Melilla, bordering Morocco.

Hundreds of migrants scaled the fence bordering Ceuta in February, amid concerns that refugee routes are shifting west following the EU-Turkey deal to stop crossings over the Aegean Sea and violence in Libya.

More than 8,000 asylum seekers crossed the Mediterranean Sea to Spain by boat last year and the figure is expected to be surpassed in 2017.

More than 3,300 people have made treacherous sea journeys from North Africa to the Spanish mainland so far this year, with at least 60 dying in the attempt according to International Organisation for Migration figures.

In pictures: A day of refugee rescues in the Mediterranean Sea Show all 7 1 /7 In pictures: A day of refugee rescues in the Mediterranean Sea In pictures: A day of refugee rescues in the Mediterranean Sea A baby being taken on to MSF's Bourbon Argos ship from a boat carrying 130 migrants and refugees Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A refugee boat carrying 101 people being rescued by MSF's Bourbon Argos Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A refugee boat carrying 101 people being rescued by MSF's Bourbon Argos all images by Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A baby among refugees on a boat carrying 185 people off the coast of Libya Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea Migrants and refugees sleeping after being rescued by MSF's Bourbon Argos ship Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A crew from MSF's Bourbon Argos ship rescuing a boat carrying 130 migrants and refugees off the coast of Libya, at sunrise Lizzie Dearden In pictures: A day of refugee rescues in the Mediterranean Sea A woman in a stretcher being lifted onto MSF's Bourbon Argos ship from a boat carrying 130 migrants and refugees off the coast of Libya Lizzie Dearden

The vast majority of journeys are made between Libya and Italy, which has become the deadliest sea passage in the world during the refugee crisis.

It has claimed more than 2,000 lives so far this year, with 8,900 refugees rescued on Sunday and Monday alone amid concern over capacity for rescue missions.

All ships at the scene of continuing rescues on Tuesday reported that they were full, even as new migrant boats were spotted approaching on the horizon.

The EU is increasing cooperation with the fragile Libyan Government of National Accord to crack down on smuggling gangs but has been criticised for failing to bolster rescue efforts and prevent deaths.

NGO rescue ships, naval vessels, Frontex assets and commercial ships are being deployed by Italian commanders who are coordinating operations in international waters from Rome.

The vast majority of asylum seekers currently making treacherous sea journeys to Europe are from African nations including Guinea, Nigeria, the Ivory Coast and Gambia, as well as Bangladesh, Syria and Iraq.