
From the disturbing image of a drugs-addicted prostitute smoking a cigarette, to a haunting picture of a desperate mother standing alone amidst the devastation of the Japanese Tsunami - the World Press Photo contest offers a vivid reflection of the world we live in.

An exhibition of the winning entries, which went on show at the Southbank Centre in London today showcases the best in photojournalism from across the globe and features startling pictures from the world in 2011.

This year's top prize was awarded to Spanish photographer Samuel Aranda for his image of a mother cradling her son in her hands after he has been overcome by tear gas during an anti-government demonstration in Yemen.

Tragic: This work by Brent Stirton won first prize in the Contemporary Issues Singles category. it shows Maria, a drug-addicted sex worker, resting between clients in the room she rents in Kryvyi Rih, Ukraine. The country has the highest incidence of HIV/Aids in Europe, according to UNICEF Winner: This haunting image by Samuel Aranda was named press World Press Photo of the Year for 2012. It shows Fatima al-Qaws cradling her son Zayed (18), who is suffering from the effects of tear gas after participating in an anti-government demonstration, in Sanaa, Yemen, in October last year

The winning images were selected from more than 100,000 pictures that were originally submitted by over 5,000 photographers.

The stunning collection will be on display at the Southbank Centre, Royal Festival Hall, until November 27.

Categories included in the exhibition include 'Spot News,' 'General News,' 'People in the News,' 'Contemporary Issues' and 'Daily Life.'

'Tsunami': Yasuyoshi Chiba won first prize in the People in the News Stories category for this moving work. Chieko Matsukawa is pictured holding up her daughter's graduation certificate, which she salvaged from the ruins of their home in Higashimatsushima. On 11 March last year, a magnitude 9 earthquake triggered a tsunami that swept inland over an area of some 500 square kilometers leaving a path of destruction in its wake

'World Aquatics Championships:' Divers practice during the second day of the 14th FINA World Aquatics Championships, in Shanghai, China, in July 2011. The photo, by Australian Adam Pretty, won second prize in the Sports Stories category

'On Revolution Road': Rebels battle against government forces for Ras Lanuf, an oil-refining town on the Libyan coast, on 11 March last year. Ras Lanuf had fallen to anti-government forces on 4 March, during their initial advance west, towards the capital Tripoli. After heavy bombardment by land, sea and air, government forces retook the city on 10 March, and began pushing the rebels back. This picture, by Yuri Kozyrev won first prize in the Prize Spot News Singles category

'Cliff-climbing polar bear attempting to eat seabird eggs': A young male polar bear climbs on a cliff face above the ocean at Ostrova Oranskie, in northern Novaya Zemlya, Russia, attempting unsuccessfully to feed on eggs from the nests of Brünnich's guillemots, early last July. The photo by Jenny E. Ross, won first prize in the Nature Singles category

Among the startling images was a photo of rebel fighters scattering during a battle against the forces of Colonel Muammar Gaddafi in Libya in February 2011, a picture of a new recruit to the Afghan police force and guards protecting a rare white rhino in Kenya.

The pictures also captured the colourful side of life on Earth, with a shot of a model resplendent in red being prepared to take part in last year's Dakar Fashion Week, and a singer performing in a Russian resort on the Black Sea coast.

The sporting world was also shown, with a dramatic scene from a rain-lashed rugby match in Ireland to the elegant sight of divers taking part in the World Aquatics Championships in Shanghai, China.

Haunting profiles: 'Afghan police recruits' (left) shows a new recruit at a police training center run by Germany, in Kunduz, Afghanistan in September 2011. The picture, by Ton Koene, won 2nd prize in the Portraits Stories section. 'Danish and Iranian culture': (right) shows actress Mellica Mehraban, who was born in Iran but grew up in Denmark. She played a lead role in the Iranian spy thriller 'Fox Hunting.' The picture, by Laerke Posselt won first prize in the Portraits Singles category

'Rhino Wars': An anti-poaching team guards a northern white rhino, part of a 24-hour watch, at Ol Pejeta Conservancy in Kenya last July. The park is home to four of the world's remaining eight northern white rhinos.

'Dakar fashion week': A model poses in front of a tailor's stall in the centre of Dakar, Senegal during the ninth edition of the Dakar Fashion Week last July. She is wearing a dress by US-based Senegalese designer Yolande Ngom Mancini. (Photograph by Vincent Boisot won second prize in the Arts and Entertainment Singles category)

'The Sochi Project - Sochi Singers': Marika Bajur sings 'Kuriu,' in the restaurant Eurasia in the Russian resort city of Sochi last January. The resort is on the eastern coast of the Black Sea. Greater Sochi sprawls for some 145 kilometers along the shore, attracting predominantly Russian holidaymakers, who come for the sun, sea, sand, and nightlife. (Picture by Rob Hornstra won first prize in the Arts and Entertainment Stories category)

Ordinary life was also featured, with an image of an elderly couple living in Buenos Aires after 65 years of marriage and an illuminated portrait of North Korea's first president Kim Il-Sung among a backdrop of grey buildings.

The political world is documented with a dramatic shot of protesters in Cairo's Tahrir Square, while a tragic image of clothes left on the shore of the island of Utoya by youngsters desperately fleeing from gunman Anders Behring Breivik.

The force of nature is shown in a photo by Paolo Pellegrin which shows a large ship stranded on dry land, surrounded by debris left by the huge tsunami which swept part of Japan in April 2011.

'Never Let You Go': Marcos and Monica were married for 65 years and, for much of that time, lived in the same apartment in Buenos Aires. In 2007, aged 84, Monica was diagnosed with Alzheimer's. Marcos looked after her himself, coping with the emotional and physical stress of being a caregiver. (Picture, taken in May 2009, by Alejandro Kirchuk won first prize in the Daily Life Stories section)

'Mubarak steps down,': Demonstrators in Tahrir Square, Cairo, react to a televised speech on 10 February 2011, in which contrary to prior expectations, Egypt's president Hosni Mubarak said he would not give up power. Since late January, protests against Mubarak's 30-year-old regime had been held nationwide, with Tahrir Square as an increasingly volatile focal point. (Picture by Alex Majoli won first prize in the General News Singles category)

'Scrum half': Blackrock College scrum-half Conor Crowley releases the ball after a ruck, during a Division 1A All-Ireland League rugby union match against Old Belvedere, in heavy rain on 5 February 2011, at Anglesea Road, Old Belvedere's home stadium. (Picture by Ray McManus won second prize in the Sports Singles category)

The first World Press Photo award was held in 1955 when members of the Dutch photojournalists’ union turned their national competition into an international one.

The competition has been held almost every year since then with winning pictures being put together into an exhibition.

In 1955, 42 photographers from 11 countries submitted just over 300 photographs for judging. Today the annual contest attracts well over 5,000 participants from around 125 countries, who together send in tens of thousands of images.

'North Korea': A portrait of North Korea's founder, Kim Il-sung, decorates a building in the country's capital Pyongyang. The 'Great Leader,' as he was known, was succeeded by his son Kim Jong-il, in 1994. (Picture by Damir Sagolj won first prize in the Daily Life Singles category)

'Tsunami aftermath': Tsunami waves created by a massive earthquake off the northeastern shores of Japan caused wide-ranging destruction along the coast. Iwate, Miyagi, and Fukushima the three worst-hit prefectures were overwhelmed by an estimated 22.63 million tons of debris. (Picture which shows damage in Kesennuma, Miyagi prefecture, on 14 April 2011 was taken by Paolo Pellegrin. It won second prize in the General News Stories category)