US President Joe Biden has condemned the taking of hostages in a synagogue in the US state of Texas as an act of terrorism.

"It was an act of terrorism," Biden said on the sidelines of an appointment in Philadelphia on Sunday.

The Democrat praised the police's action, in which all hostages were released unharmed.

"They just did a great job."

A man took several hostages in a synagogue in the city of Colleyville near Dallas on Saturday. After hours of negotiations with the kidnapper, special forces entered the building in the evening (local time) and freed the hostages. These remained unharmed. The hostage-taker died. Exactly how, the police initially left open. The authorities were also officially covered about the background. US media reported, citing investigators, that the kidnappers wanted to free a Pakistani scientist imprisoned in Texas, who was convicted in 2010 of attempting to murder American soldiers in Afghanistan.

The police announced the identity of the hostage-taker on Sunday: it was a 44-year-old British citizen.

There is currently no evidence that other people were involved, it said.

The man took four hostages during a service in the synagogue in the city of 26,000 on Saturday morning and holed himself up with them in the building for hours.

Among them was the rabbi.

Church service streamed

The service was streamed live on the church's Facebook page.

The local newspaper, the Fort Worth Star Telegram, reported that the voice of an angry man could be heard in the live stream, ranting and cursing and talking about religion, among other things.

He said several times that he didn't want to hurt anyone and that he believed he was going to die.

At some point the transmission stopped.

The police arrived with a large contingent of around 200 officers, including special units specializing in hostage-taking.

Specialists from the Federal Police FBI kept in touch with the hostage-taker throughout the day and negotiated with him.

The situation was unclear for a long time.

The first all-clear came early in the evening: a male hostage was released – unharmed.

A few hours later, Texas Gov. Greg Abbott tweeted that all the hostages were free and safe.

FBI official Matt DeSarno said all four hostages were safe and unharmed.

The hostage-taker has been identified.

In view of the ongoing investigation, the police could not provide any further information about him.

Extensive investigations into his motive and possible contacts are underway.

"Our investigations will have global reach," DeSarno said.

According to reports, hostage-takers are British

DeSarno said the hostage-taker was known to be focused on an issue not specific to the Jewish community.

Colleyville Police Chief Michael Miller said it was not yet clear why the man targeted the local synagogue.

Several US media, including the Washington Post and broadcaster CNN, reported, citing investigators, that the man wanted to secure the release of Pakistani scientist Aafia Siddiqui from a nearby prison in Texas.

Siddiqui was arrested in Ghasni, Afghanistan, in July 2008 and sentenced by a US federal judge to 86 years in prison in 2010 for an attack on US soldiers in Afghanistan.

During interrogation at a police station, she took a gun lying on the ground and aimed it at an American soldier and a translator, without hitting them.

Siddiqui was previously educated at one of the top universities in the US, MIT in Cambridge.

Later, American authorities added her name to a list of suspects linked to al-Qaeda terrorists.

Bennett is relieved to be freed

The police did not comment on the motive of the perpetrator in Texas.

Initially, it also remained unclear how the scene of the hostage rescue took place, how the hostage-taker was armed and whether he was killed by officials or possibly took his own life.

Israeli Prime Minister Naftali Bennett tweeted his relief and gratitude after the hostages were freed.

"This incident made it clear to us that anti-Semitism is still alive and that we must continue to fight it worldwide."

Authorities in other American cities, including New York and Los Angeles, said they had initially increased their presence at synagogues and Jewish institutions in light of the hostage-taking.