Gunfire

Pro-Russia militants fire at Ukrainian border guards defending the Federal Border Headquarters in Lugansk, eastern Ukraine, on June 2, 2014. Ukrainian forces killed five rebels on June 2 while repelling an attack by 500 pro-Russian gunmen on a federal border guard camp in the strife-torn separatist east, Kiev officials said. The border guard service said seven of its servicemen were wounded when "around 500 terrorists" attacked one of its units stationed outside the industrial city of Lugansk.

Sergey Gapon/AFP

Pro-Russia militants fire at Ukrainian border guards defending the Federal Border Headquarters in Lugansk, eastern Ukraine, on Monday

A woman runs for cover as heavy gunfire erupts in the Miskin district of Bangui, Central African Republic, Monday Feb. 3, 2014. In what a French soldier on the scene describes as the heaviest exchange of fire he'd seen since early December 2013, Muslim militias engaged Burundi troops who returned fire. A third source of firing remained unidentified. Fighting between Muslim Seleka militias and Christian anti-Balaka factions continues as French and African Union forces struggle to contain the bloodshed.

Jerome Delay/AP

A woman runs for cover as heavy gunfire erupts in the Miskin district of Bangui, Central African Republic. In what a French soldier on the scene describes as the heaviest exchange of fire he had seen since early December, Muslim militias engaged Burundi troops who returned fire.

WATERTOWN, MA - APRIL 19:  Police with guns drawn search for a suspect on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. It's not clear whether the shootings are related or whether either are related to the Boston Marathon bombing.

Mario Tama/Getty

Police with guns drawn on Friday search for a suspect in Watertown, Massachusetts. A Massachusetts Institute of Technology campus police officer was shot and killed late on Thursday night at the school’s campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge.