(Reuters) – A hostage taker who was killed in a Texas synagogue’s attack on the building got his guns off the streets, President Joe Biden stated Sunday. This came a day following the release of four victims held by a gunman, which Biden described as “an act terror.”

The hostage incident in Colleyville, Texas, “was an act of terror; it 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.

Biden discussed the need to take action against 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.

The FBI Hostage Rescue Team stormed Congregation Beth Israel, Colleyville on Saturday night. This ended a 10 hour standoff between the gunman and police, which saw him disrupt a Sabbath worship service and take the rabbi as well as three others hostage.

After being detained for six hours, one hostage was freed uninjured and three others were released by the FBI.

Late Saturday, witnesses at the scene reported hearing the sounds of flashbangs and explosions at Colleyville’s Reform Jewish synagogue. It is located approximately 16 miles (16 km) northeast Fort Worth.

In a response to questions from media about the shooter at the synagogue, the British foreign office confirmed Sunday the death in Texas of a British citizen.

The Colleyville Police Department SWAT team responded to emergency calls that began around 10:41 am during the Sabbath worship, which was being streamed online. FBI negotiators immediately made contact with the man and he said that he wanted to meet a woman in federal prison.

A Facebook (NASDAQ) livestream recorded the man having an unidirectional phone conversation. According to the Fort Worth Star-Telegram, the man was heard talking about religion and his sister and repeatedly stating that he didn’t want anyone hurt.

According to a U.S official, the hostage-taker said that he was Aafia Siddiqui’s brother and is currently in a U.S. jail sentence for her 2010 shooting attack on soldiers. He also demanded she be released.

Siddiqui currently resides in Fort Worth’s federal prison. Marwa Elbially (a lawyer for Siddiqui) stated to CNN that Siddiqui was not her brother. Siddiqui and his family strongly condemned the “heinous” acts.

The Texas hostage crisis appeared to have been isolated. However, New York synagogues and other institutions around the country increased security in response.