The Observer's 20 photographs of the week

A portrait of a young protester in Bahrain by Mohammed Al-Shaikh, a regular contributor to this gallery, as demonstrations against the Bahrain Grand Prix continued Photograph: Mohammed Al-Shaikh/AFP

Members of a police SWAT team exit Lincoln Street moments after 19-year-old bombing suspect Dzhokhar A Tsarnaev was apprehended in Watertown, Massachusetts Photograph: Spencer Platt/Getty

Egyptian protesters clash near a bus belonging to Muslim Brotherhood supporters burns after it was reportedly set alight by anti- government protesters in Cairo, Egypt Photograph: Mostafa Elshemy/AP

Actress Tilda Swinton sleeps in a box for her performance piece called 'The Maybe' at the Museum of Modern Art in New York Photograph: Keith Bedford/Reuters

Photographer Dimitar Dilkoff continued his excellent work in Syria. Here, a Syrian boy holds an AK-47 assault rifle in Aleppo Photograph: Dimitar Dilkoff/AFP

And here, a boy holds a satellite antenna as he travels on the back of a truck in Aleppo – 1.3 million people have so far fled Syria to neighbouring countries since the beginning of the conflict Photograph: Dimitar Dilkoff/AFP

The coffin of Margaret Thatcher arrives on a gun carriage drawn by the King's Troop Royal Horse Artillery during her ceremonial funeral at St Paul's Cathedral in central London Photograph: David Crump/AFP

A man comforts a victim on the sidewalk at the scene of the first explosion near the finish line of the 117th Boston Marathon Photograph: Boston Globe/Getty

An Arab-Israeli protester on a horse holds a Palestinian flag during a march in support of the right of return for Palestinian refugees who fled their homes or were expelled during the 1948 war Photograph: Ammar Awad/Reuters

This new Hubble image, captured and released by the ESA-Nasa Hubble Heritage to celebrate the telescope's 23rd year in orbit, shows part of the sky in the constellation of Orion Photograph: AFP

A marathon runner prepares herself as spectators watch at Kim Il-sung Stadium in Pyongyang, North Korea Photograph: Alexander F Yuan/AP

In another unusual scene from Pyonyang by Alexander F Yuan, a dancing group performs during a mass folk dance Photograph: Alexander F Yuan/AP

A Bahraini policeman walks past tyres burning during clashes between demonstrators and riot police following a protest against the Bahrain Formula One Grand Prix Photograph: Mohammed al-Shaikh/AFP

A refugee woman waits for medication at a treatment centre run by humanitarian organisation Médecins Sans Frontières at the Yida camp in South Sudan Photograph: Reuters

Afghan refugee children play on wooden carts left on a roadside next to a poor neighbourhood on the outskirts of Islamabad, Pakistan Photograph: Muhammed Muheisen/AP

Sunderland's new manager Paolo Di Canio celebrates after his team scored in the vital win against rivals Newcastle United Photograph: Ian MacNicol/AFP

If Sunderland avoid relegation, they will be joined by Cardiff City in the Premiership. Here, Leon Barnett celebrates promotion with the Cardiff fans Photograph: Nick Potts/PA

Supporters of opposition leader Henrique Capriles face off against riot police as they demonstrated for a recount of the votes in last Sunday's election in Caracas, Venezuela Photograph: Christian Veron/Reuters

Indonesian rescue workers help remove a section of a Lion Air Boeing 737 from the sea four days after it crashed while trying to land at Bali's airport Photograph: Sonny Tumbelaka/AFP

Lola and her daughters, Isabel and Alejandra, wearing typical Sevillana outfits pose for a portrait during the traditional Feria de Abril in the Andalusian capital of Seville Photograph: Marcelo del Pozo/Reuters