The 20 photographs of the week

The most powerful photojournalism again came from the streets of Ukraine and Venezuela this week. Here, a woman watches from behind the tinted window of a bus at a rally against the breakup of the country in Simferopol, Ukraine. Photograph: Vadim Ghirda/AP

Colonel Yuli Mamchor, commander of the Ukrainian military garrison at the Belbek airbase, speaks to troops under Russian command who are occupying the airbase in Crimea Photograph: Sean Gallup/Getty

Russian President Vladimir Putin signs his name as he visits the Paralympic village outside Sochi Photograph: Aleksey Nikolskyi/AFP

Venezuelan National Guard members arrest an opposition activist for protesting against the government of President Nicolas Maduro in Caracas Photograph: Juan Barreto/AFP

A member of Oscar Pistorius' legal team reaches out to him as he covers his ears while a witness gives testimony and recounts the night of the crime during his trial for the murder of his girlfriend Reeva Steenkamp Photograph: Marco Longari/AFP

Australian journalist Peter Greste of Al-Jazeera and his colleagues stand inside the defendants cage during their trial for allegedly supporting the Muslim Brotherhood at Cairo's Tora prison Photograph: Khaled Desouki/AFP

A model presents a design by Sarah Burton from her Fall/Winter 2014-2015 women's collection for Alexander McQueen during Paris fashion week Photograph: Gonzalo Fuentes/Reuters

A model displays a design by Iris Van Herpen in a vacuum pack again at Paris fashion week. Photograph: Patrick Kovarik/AFP

A Syrian refugee woman looks out of a window without glass at a house in the Kucukpazar area of Istanbul. Syrian government forces are waging a campaign of siege warfare and starvation against civilians as part of its military strategy, a UN-mandated inquiry reported Photograph: Gurcan Ozturk/AFP

A Pakistani woman mourns the death of her daughter, who was killed in a twin suicide bombing, outside a hospital's morgue in Islamabad, Pakistan Photograph: Muhammed Muheisen/AP

Photographer Siegfried Modola continued his strong work from the Central African Republic. In this photograph, a girl walks through rubble of demolished Muslim homes in the capital Bangui Photograph: Siegfried Modola/Reuters

Thousands of Ultra Orthodox Jews gather in Jerusalem to demonstrate against plans to make them undergo military service Photograph: Thomas Coex/AFP

Lupita Nyong'o and Matthew McConaughey walk offstage after posing with their awards for best supporting actress and best actor at the Academy Awards in Hollywood Photograph: Mario Anzuoni/Reuters

Also at the Oscars, host Ellen DeGeneres poses for a selfie taken by Bradley Cooper with Jared Leto, Jennifer Lawrence, Channing Tatum, Meryl Streep, Julia Roberts, Kevin Spacey, Brad Pitt, Lupita Nyong'o, Angelina Jolie, Peter Nyong'o Jr and Bradley Cooper. Photograph: Ellen DeGeneres/Handout/Getty

Snakes are collected and rolled before putting into the oven in the village of Kartasura, Indonesia Photograph: Nurcholis Anhari Lubis/Getty

A horse is rescued from a pit beside railway tracks in Jalandhar, Punjab Photograph: AP

Wrestlers are photographed by regular contributor to the 20 photos of the week, Danish Siddiqui, at a traditional Indian wrestling centre in Mumbai Photograph: Danish Siddiqui/Reuters

A partially frozen Niagara Falls is photographed by Mark Blinch during sub zero temperatures in Ontario Photograph: Mark Blinch/Reuters

Bahraini protesters wearing masks take cover behind a shield during clashes with riot police in the village of Daih, Bahrain, following a rally to protest against the death of Jaffer al-Durazi who died in hospital last week. Durazi, 23, had been detained by the Bahraini authorities since December 2013 Photograph: Mohammed Al-Shaikh/AFP

Finally back to Ukraine, a teenager looks out at the countryside from a train on the outskirts of the Crimean city of Simferopol. As the standoff between the Russian military and Ukrainian forces continues in Ukraine's Crimean peninsula, world leaders are pushing for a diplomatic solution to the escalating situation Photograph: Spencer Platt/Getty