Boston police comb Watertown for bombing suspect – in pictures

Members of a Swat team search for 19-year-old bombing suspect Dzhokhar A Tsarnaev Watertown, Massachusetts Photograph: Mario Tama/Getty Images

Law enforcement officers react to what was initially thought to be a threatening suspect on Arsenal Street, in the search area for Dzhokar Tsarnaev, in Watertown Photograph: Lucas Jackson/Reuters

A Boston Swat member takes up as posistion as they search for 19-year-old bombing suspect Dzhokhar Tsarnaev in Watertown Photograph: Mario Tama/Getty Images

Residents watch as policemen search for suspect in Cambridge Photograph: Xinhua /Landov / Barcroft Media/Barcroft Media

A Boston police officer searches outside of South Station for suspicious material after two bullets were found outside of the T stop in Boston Photograph: Kayana Szymczak/Getty Images

Stranded travelers wait outside South Station in Boston Photograph: Kayana Szymczak/Getty Images

Snipers take positions on a rooftop during the manhunt in Watertown Photograph: John Mottern/AFP/Getty Images

A Swat officer talks to a resident as their team searches neighborhoods yard by yard after a police chase in Watertown Photograph: Matt Campbell/EPA

Ruslan Tsarni, uncle of the suspected Boston Marathon bombing suspects, walks with a neighbor in Montgomery Village, Maryland. Tsarni asked the still-at-large bombing suspect Dzhokhar Tsarnaev to turn himself in Photograph: Allison Shelley/Getty Images

A resident watches from her window as police search an apartment complex in Watertown Photograph: CJ Gunther/EPA

State police colonel Timothy Alben speaks to the media on Arsenal Street after a night of violence in Watertown Photograph: Rex Features/Zuma

A woman looks out a window at her home as police start to search an apartment building while looking for a suspect in the Boston Marathon bombings in Watertown Photograph: Charles Krupa/AP

Police in the School Street and Walnut Street area in Watertown, Massachusetts Photograph: Darren McCollester/Getty Images

An FBI Swat team member shouts as his team surrounds a house Photograph: Matt Campbell/EPA

A member of an FBI Swat team outside a house while they follow a tracking dog Photograph: Matt Campbell/EPA

The scene of the shootout in Watertown Photograph: Barcroft Media

The scene of the shootout involving the Boston bomber suspects in Watertown. The incident happened in a normally quiet, suburban street Photograph: Barcroft Media/Barcroft Media

Swat team members hang off the back of a truck as they prepare to search the neighborhood for the remaining suspect Photograph: Darren McCollester/Getty Images

Police officers outside a shopping mall on the perimeter of the locked-down area as a search for the second of two suspects wanted over the Boston Marathon bombings takes place Photograph: Stan Honda/AFP/Getty Images

An elderly woman is helped away from the area Photograph: Darren McCollester/Getty Images