In an attempt to address the lack of diversity among Thomas the Tank Engine’s friends - and sell more merchandise in foreign markets - manufacturer Mattel has announced 14 new international locomotive pals will be joining the television show.

Among them will be Yong Bao, Carlos and Ashima, from China, Mexico and India respectively, while the rest will consist of trains from all corners of the world. Only four will be female.

According to the New York Times, the new characters will be introduced in the movie The Great Race, set to hit UK cinemas this May and receiving a staggered worldwide DVD release later on in the year. So far, four new engines have been unveiled, all of which you can see in the gallery below.

Thomas the Tank Engine's new international friends Show all 4 1 /4 Thomas the Tank Engine's new international friends Thomas the Tank Engine's new international friends Carlos from Mexico Carlos is - according to Mattel - “proud” and “always wearing a smile.” Carlos’s red, green and black design is modelled after the Ferrocarriles Nacionales de México locomotive known as No. 903. Thomas the Tank Engine's new international friends Ashima of India Ashima “shows no fear” and is “happy to help out.” According to Vincent D’Alleva, who oversees the show Thomas & Friends: “She is the first one who can take on Thomas in terms of being the fastest engine. It’s not a romance story because, well, that’s not something for our target audience. But it is about developing a relationship. How does Thomas develop a relationship with someone who looks very different from him and in some cases can do things better than he can?” Thomas the Tank Engine's new international friends Yong Bao of China Bao is “driven to achieve and make progress.” The ever expanding market of China has become a central target for the Toy company. It is their second biggest territory, behind the US and just ahead of the UK. Thomas the Tank Engine's new international friends Raul of Brazil According to Mattel, Raul is “feisty,” “strong and agile.” D’Alleva told NYTimes that the upcoming film will focus on the Olympic Games in Rio de Janeiro, so expect Raul to play a big part.

While D’Alleva explained that the new characters were designed to represent the countries they come from, many commentators have voiced concern over possible racial stereotyping.

Tracey Van Slyke, a researcher in social justice and pop culture who has previously criticised the show for having a “little white boss” dictate what tasks the engines do, told The Telegraph: “I applaud the idea, but am concerned about execution.

“There is a danger in reducing very complex countries and peoples to singular characteristics. If the trains are only defined by cultural stereotypes, the result will be a calculated, and destructive, nod to diversity and inclusivity”.

Thomas the Tank Engine was created by Rev Awdry, a vicar in the parish of St Nicholas, Birmingham. After first telling his tale of the anthropomorphised train in 1942 to his son, he went on to send three stories to a publisher after being encouraged by his wife.

Thomas the Tank Engine will steam into 2013 as the “King of the Railway” (PA)

In 1945, The Three Railway Engines was published, becoming a huge success and resulting in a further 26 Railway books being published.

Rev Awdry passed died in 1997, with his daughter Veronica Chambers, saying of the new characters: “I think they have tried to expand Thomas cultural outlook.”

When asked whether he would have approved of the move, she added: “What he would have been pleased about was to think that Thomas is still bringing such joy and pleasure to grown-ups all over the world.

Thomas the Tank Engine was attacked in Canada for having only eight female characters out of 49 and having a “conservative political ideology” that saw Thomas slaving away for the Fat Controller (Rex)

“And in everything Mattel have done they have strictly adhered to the right railway practice. All the new characters, introduced are based as far as possible on actual locomotives.”