At least five Dallas area police officers have been killed, while seven others were wounded after snipers opened fire at officers during a Black Lives Matter protest. Here we take a closer look at those killed and the lead-up to the incident.
Five police officers providing security for a Black Lives Matter protest were killed and six others were injured after a sniper opened fire on them in Dallas, Texas on Thursday.
The demonstration was organised in response to the fatal shootings of two black men by the police this week in Louisiana and Minnesota.
Alton Sterling, 37, was shot four to six times in the chest and back after an altercation with police officers outside a Baton Rouge convenience store. Two officers have been placed on administrative leave following the deadly shooting.
Sterling was a father of five. Close friends and relatives described him as jovial and friendly – a fixture of the neighbourhood who sold copied CDs, DVDs and games in front of the store where he was killed for years.
The US Justice Department on Wednesday said that it would investigate the killing of Mr Sterling. Baton Rouge Mayor-President Kip Holden and the Baton Rouge Police Department have stated that they welcomed the probe initiated by the Justice Department, FBI and federal prosecutors.
A day later, another deadly shooting took place in Falcon Heights, Minnesota. The aftermath of the fatal shooting of Philando Castile, 32, by police was captured in graphic detail by his girlfriend in a live Facebook stream.
Mr Castile was pulled over for having a broken taillight. His girlfriend and her daughter were in the car with him. In the 10 minute video, Mr Castile is seen in the drivers seat, large blood stains spreading through his white shirt.
Speaking at a news conference, Minnesota Governor Mark Dayton said an investigation into the shooting of Mr Castile was underway.
"This kind of behaviour is unacceptable," Mr Dayton added.
US President Barack Obama, reacting to the incidents said the shootings were evidence of a "serious problem" in US society and it was clear the shootings were not "isolated incidents."
"All Americans should be deeply troubled by the fatal shootings of Alton Sterling in Baton Rouge, Louisiana and Philando Castile in Falcon Heights, Minnesota.
"They are symptomatic of the broader challenges within our criminal justice system, the racial disparities that appear across the system year after year, and the resulting lack of trust that exists between law enforcement and too many of the communities they serve," President Obama said in a statement on Facebook.
The ambush on Dallas police officers may have stemmed from the increasing distrust and hate towards the police from the very communities they are sworn to protect. According to reports, a gunman who was killed during a shootout with the police said he was angered over racially charged shootings and wanted to kill white people.
Officers Brent Thompson and Patrick Zamarripa were the first victims to be identified after the shootout in Dallas today.
Brent Thompson, 43, had worked as an officer for the Dallas Area Rapid Transit (DART) transport system since 2009. He is the first officer from DART to be killed in the line of duty since its inception.
James Spiller, chief of the Dallas Area Rapid Transit (DART) Police Department, speaking to local TV station WFAA said Thompson had been in "great spirits from his recent marriage," Thompson's bride was another DART officer, the station reported.
A member of the Dallas Police Department's response team, Patrick Zamarripa, 32, had been on the Dallas police force for about five years and was a devoted husband and father to a two-year-old daughter, his family said.
Before joining the police force he served three tours in Iraq as a Navy veteran.
His stepmother Maria Zamarripa, after hearing about the sniper gunning down cops at the rally, sent a text to his son at 10pm.
Shortly after that she was called to the Parkland Memorial Hospital and given the news she feared the most – that her son was one of the five officers slain in the attack.
"I was told he passed away at 9:17. So he would have never seen my text," Maria Zamarripa told the Daily News as she fought back tears. "We were always worried about something happening to him."
The last time she saw her son was last weekend when he picked his daughter up from her house and discovered that she was learning to talk.