WASHINGTON, Oct. 27 (Xinhua) -- A Pennsylvania gunman alleged to have killed 11 people at a synagogue in Pittsburgh Saturday has been charged with 29 counts of violence and firearms offenses, according to U.S. federal prosecutors.

The charges against Robert Bowers, 46, include 11 counts of using a firearm to commit murder and multiple counts of two hate crimes: obstruction of exercise of religious beliefs resulting in death and obstruction of exercise of religious beliefs resulting in bodily injury to a public safety officer.

"The crimes of violence are based upon the federal civil rights laws prohibiting hate crimes," the U.S. Attorney's Office of the Western District of Pennsylvania said in a statement.

It is unknown yet if Bowers has an attorney.

The FBI in Pittsburgh is leading the investigation, the statement added.

U.S. Attorney General Jeff Sessions said in a statement Saturday afternoon that the Department of Justice would "file hate crimes and other criminal charges against the defendant, including charges that could lead the death penalty."

Besides the 11 fatalities, authorities said six people, including two police officers and two SWAT officers, were also injured during Saturday's shooting. The suspect suffered multiple gunshot wounds and is in fair condition.

The initial call to the police was made around 9:54 local time (1354 GMT) and officers were dispatched to the scene within a minute, authorities said.

Police sources told local CBS affiliate KDKA that the gunman, armed with what appeared to be an assault rifle and at least three handguns, yelled "all Jews must die" before opening fire.

Bowers' social media posts were reportedly rife with anti-Semitic content.

The synagogue is located at the intersection of Wilkins and Shady avenues. The neighborhood of Squirrel Hill, about 10 minutes of drive from downtown Pittsburgh, is the hub of the city's Jewish community.

The synagogue offers members a "traditional Conservative service with a modern sense of family" and shabbat service on 9:45 a.m. Saturdays, according to the Tree of Life's website.

U.S. President Donald Trump has ordered flags at federal buildings throughout the country to be flown at half-staff in "solemn respect" for the victims.

Earlier in the day, the president told reporters he would travel to Pittsburgh, but offered no details.