The Observer's 20 photographs of the week

Reuters photojournalist Ahmed Jadallah continues to produce critical work from Aleppo in Syria. Here he photographs a Free Syrian Army fighter dragging a boy off the street away from sniper fire. On the same day, the photographer was working with Reuters cameraman Ayman al-Sahili when he was shot in the leg Photograph: Ahmed Jadallah/Reuters

Photographer Jure Makovec was on Smarna Gora, the highest hill in Ljubljana, to take this image of fireworks rising above clouds during New Year celebrations Photograph: Jure Makovec/AFP

Observations made with the ALMA (Atacama Large Millimeter Array) telescope show the disc of gas and cosmic dust around the young star HD 142527. The vast streams of gas are believed to be created by giant planets guzzling gas as they grow Photograph: M Kornmess/ESO/EPA

Muhammed Muheisen, a regular to the Observer's 20 photographs of the week, took this striking image of Pakistani schoolgirls paying tribute to the five female teachers and two aid workers killed by gunmen in northwest Pakistan on Tuesday Photograph: Muhammed Muheisen/AP

Ricardo Moraes covered the flooding of the Capivari river near Rio de Janiero. At least 255 people were displaced and one person died Photograph: Ricardo Moraes/Reuters

In a more abstract image, Moraes photographed these cats at a flood-damaged house Photograph: Ricardo Moraes/Reuters

A bullfrog is accounted for at the photogenic annual stocktake of animals at London Zoo Photograph: Dan Kitwood/Getty

Meanwhile, at Berlin Zoo, an elephant eats a tree at the annual feeding of Christmas trees Photograph: Markus Schreiber/AP

A boy pulls in nets as he tries to make a living selling fish on the shores of the river Ubangi in the Central African Republic. The country's president Francois Bozize consolidated his military power after dismissing his own son as acting defence minister as government forces remain at a tense standoff with rebels Photograph: Ben Curtis/AP

But here people look desperate to leave Damara, the last strategic town between the rebels and the country's capital Bangui. The commander of the regional African force FOMAC warned rebels against trying to take the town, saying it would 'amount to a declaration of war' Photograph: Sia Kambou/AFP

The death of a 23-year-old woman raped on a New Delhi bus triggered street protests across India and a national debate about violence against women. Here, women enter Raj Ghat to attend a prayer ceremony for the rape victim Photograph: Adnan Abidi/Reuters

X-ray photography revealed an intriguing painting dimly visible beneath a portrait of Sir Francis Walsingham, Queen Elizabeth I's loyal spymaster. His portrait was secretly painted over an overtly Roman Catholic image of the holy Virgin and Child. The National Portrait Gallery opened a display showing x-rays of devotional paintings it has discovered underneath two Tudor portraits Photograph: National Portrait Gallery, London

In central Gaza, a Palestinian Fatah supporter waves a flag while standing in a tree during a rally marking the anniversary of the movement. Hundreds of thousands of Palestinians attended the rally in a rare show of support for the leader Mahmoud Abbas Photograph: Ali Ali/EPA

Clashes continued in the village of Kafr Qaddum, near Nablus. Israeli soldiers walk through black smoke rising from burning rubber tyres set alight by Palestinians protesting against the expropriation of their land by Israel Photograph: Jaafar Ashtiyeh/AFP

Lancashire has the highest amount of empty homes in England, estimated at 850,000 properties. The terrace houses photographed here in Accrington were due to be renovated by the council but the project was put on hold when the government cut a regeneration project Photograph: Christopher Furlong/Getty

Acclaimed photojournalist Uriel Sinai covered the funeral this week of Rabbi Abraham Jacob Friedman of the Sadigura Hasidic dynasty. Here he photographs Ultra Orthodox Jewish men carrying his body during the funeral in Bnei Brak, Israel Photograph: Uriel Sinai/Getty

And here, he photographs Ultra Orthodox Jewish youth trying to find a decent viewpoint to see the funeral Photograph: Uriel Sinai/Getty

Pope Benedict XVI arrives at the Vatican to attend a meeting with members of the Taizé Community Photograph: Tony Gentile/Reuters

Dylan Martinez's image shows Pakistani schoolgirl Malala Yousafzai being discharged from The Queen Elizabeth Hospital in Birmingham. Malala was shot in the head by the Taliban for advocating girls' education in Pakistan. Doctors said she was well enough to spend some time recovering with her family Photograph: Dylan Martinez/Reuters

In Pakistan, a woman stands outside her makeshift home on a foggy morning in another strong image by Muhammed Muheisen from Islamabad Photograph: Muhammed Muheisen/AP