The U.S. President Joe Biden said a hostage taker killed at a Texas synagogue got his weapons off the street. He said this on Sunday, a day after the safe release of four people held there by a gunman in what Biden called "an act of terror."

The hostage incident in Colleyville, Texas, "was an act of terror", said Biden, who was in Philadelphia with first lady Jill Biden packing carrots and apples at a food bank in a visit to the city to honor the legacy of slain civil rights leader Martin Luther King Jr.

The U.S. President addressed the issue of measures needed to stop gun violence.

"The idea of background checks are critical, but you can't stop something like this if someone's on the streets buying something from somebody else on the streets," he said.

An FBI Hostage Rescue Team on Saturday night stormed Congregation Beth Israel in Colleyville, ending a 10-hour standoff with police by the gunman, who disrupted a Sabbath service and took the rabbi and three other people hostage.

One hostage was released unharmed after being held for six hours and the remaining three were later safely freed by the FBI team.

Reporters at the scene late Saturday said they heard the sound of explosions, possibly flashbangs, and the sound of gunfire at the Reform Jewish synagogue in Colleyville, which is about 16 miles northeast of Fort Worth.

Britain's foreign office on Sunday confirmed the death of a British man in Texas, in a statement issued in response to a media inquiry about the gunman at the synagogue.

(With input from Reuters)