Samuel Aranda has won the World Press Photo of the Year with his image of a man being cared for a field hospital in Sanaa, Yemen, during demonstrations against the rule of President Ali Abdullah Saleh. More work from this year's WPP in the post...

From the events of the Arab Spring, to the Japanese tsunami and the conflict in Libya, a turbulent 2011 certainly provided photojournalists with an unprecedented amount of material. This year's WPP Awards go some way to reflect the events of that year, plus the numerous personal stories that are entered into the competition. A selection of some of the most interesting winning work follows below.

All captions are taken from the World Press Photo site. To see the full series of photographs from the various 'Stories' sections, go to worldpressphoto.org.

People in the News, 1st prize stories, Yasuyoshi Chiba. Nozomi Sabanai (left), together with her sister, looks at a catamaran sightseeing boat thrown by the tsunami onto a two-story building, Otsuchi town, Iwate prefecture, Japan.

Daily Life, 1st prize stories, Alejandro Kirchuk. Marcos, 89, and Monica, 87, have been married and living in their apartment in Buenos Aires, Argentina, for 65 years. In 2007, Monica was diagnosed with Alzheimer's disease. Since that moment, her husband devoted all his time to take care of her.

Spot News, 1st prize singles, Yuri Kozyrev. Rebels in Ras Lanuf, Libya.

Arts and Entertainment, 1st prize singles, David Goldman. Canadian Forces soldier Cpl. Ben Vandandaigue plays the drums on Forward Operating Base Sperwan Ghar in Afghanistan.

Arts and Entertainment, 1st prize stories, Rob Hornstra. The southern Russian city of Sochi lies on the Black Sea and attracts predominantly Russian holidaymakers who come for a mix of sun, sea, sand and nightlife. Restaurants are plentiful and competition is fierce, with every restaurant employing a regular live musician blasting popular Russian songs. Here, Narek Akopyan sings 'Kayfuem' in the restaurant Sabrina.

Contemporary Issues, 2nd prize singles, Ilvy Njiokiktjien. A sergeant shows boys at a ‘kommandokorps’ camp in South Africa how to use a gun.

Contemporary Issues, 1st prize stories, Stephanie Sinclair. Maya, 8, and Kishore, 13, pose for a wedding photo inside their new home, the day after the Hindu holy day of Akshaya Tritiya in North India.

Daily Life, 1st prize singles, Damir Sagolj. A picture of North Korea's founder, Kim Il-sung, decorates a building in the capital Pyongyang.

Daily Life, 3rd prize singles, Paolo Woods. More than 50 percent of Haitians are illiterate and only 25 percent have regular access to electricity. But they can listen to the radio, and do so all the time.

Nature, 1st prize singles, Jenny E. Ross. A male polar bear climbs precariously on the face of a cliff above the ocean at Ostrova Oranskie in northern Novaya Zemlya, Russia, attempting to feed on seabird eggs.

Nature, 2nd prize stories, Carsten Peter. Hang Ken cave, on the way to Hang Son Doong, Vietnam, is the world’s biggest cave passage (sometimes up to 200 metres high).

Portraits, 1st prize singles, Laerke Posselt. The Iranian-born actress, Mellica Mehraban.

Portraits, 1st prize stories, Donald Weber. Interrogation room at a police station in Dneprodzerzhinsk, Ukraine.

Portraits, 3rd prize stories, Simon Norfolk. The future leadership of the Afghan Air Force with Maj. Jason A. Church of the US Marines, which is training and funding them. Norfolk was inspired in this project by the pictures of war photographer John Burke from the Second Anglo-Afghan War in 1878-1880, the first ever photographs made in Afghanistan.

Spot News, 2nd prize stories, Niclas Hammerström. Police helicopters circle Utøya, the small island outside Oslo in Norway where Anders Behring Breivik killed 69 people on July 22.

Sports, 3rd prize stories, Tomasz Gudzowaty. Masked luchadores at La Loba in the Chimalhuacán neighborhood of Mexico City.

Sports, 1st prize singles, Donald Miralle, Jr. Triathletes swim over a school of fish at the start of the 2011 Ford Ironman World Championship at Kailua Bay in Kona, Hawaii, considered one of the most grueling races in the world.

The full list of winners is at worldpressphoto.org.