At least six policemen were injured in a shooting incident in a northern Philadelphia neighbourhood and the suspect is still firing from inside a house, security officials said.
White House Principal Deputy Press Secretary Hogan Gidley said President Donald Trump is monitoring the situation.
The incident comes in the wake of two mass shootings within 24 hours in El Paso and Dayton earlier this month in which 30 people were killed and several others injured.
"Six PPD Officers shot at area hospitals with non-life-threatening injuries. Additional officers also receiving treatment for non-gunshot injuries... The situation is active and ongoing," spokesperson of Philadelphia Police Department Eric Gripp said.
"Officers continue to implore suspect to surrender - this can end without any further violence," he said.
Police Commissioner Richard Ross told reporters that he personally tried to talk to the shooter, but he did not respond verbally.
The shooting began around 4.30 pm. Police said they are not sure if there was one shooter or two.
"The president has been briefed on the shooting in Philadelphia and continues to monitor the situation," Gidley said.
According to the Philadelphia Inquirer, one suspect has been taken in custody, while another suspect at one point was streaming the gun battle live on Facebook.
The daily said that narcotics officers were attempting to serve an arrest warrant at the house when shots were first fired.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)