I located a number of images at Corbis and Getty Stock Photography.
Photo Number: R93058012
Police Officer Running Away From the World Trade Center
Original caption: New York: Blast: A police officer flees the World
Trade Center February 26, after a blast ripped through the world's
second-tallest office complex, killing two people and injuring 200.
Photographer: Mark Cardwell
Date Photographed: February 26, 1993
Location Information: Manhattan, New York, New York, USA
Available in low 480px x 324px and medium 1394px x 941px
Photo Number: TL034309
Policemen Dispersing a Demonstration
Armed with batons, policemen rush to disperse demonstrators marching
to Pollsmoor Prison, where Nelson Mandela is being held.
Photographer: David Turnley
Date Photographed: ca. 1986
Location Information: Athlone, Cape Town, South Africa
Available in low 424px x 640px and medium 829px x 1251px
Title: Armed Siege In East London
LONDON - DECEMBER 31: An armed policeman runs behind cover during an
armed siege December 31, 2002 in London, United Kingdom. The siege, in
its sixth day, began on Boxing Day after police were fired on as they
tried to remove a suspect vehicle. Police negotiators are on the scene
and are attempting to coax the gunman to give himself up and release
another person in the premises who police are describing as a hostage.
(Photo by Ian Waldie/Getty Images)
File Size/Pixels/DPI: 578K/3000x1937/300
Object Name: 1705394IW002_siege
8th March 1973: Disorder as people rush about after the bomb blast in
Whitehall. In the foreground are injured passers-by still in a
confused state, wondering what has happened. A policeman rushes to
someone's aid. (Photo by James Jackson/Evening Standard/Getty Images)
File Size/Pixels/DPI: 735K/2569x2580/0
I hope the images provided are helpful!