This AFP video screengrab shows Police Chief Michael Miller speaking to the press after the liberation of the Congregation Beth Israel synagogue hostages in Colleyville, Texas, some 25 miles (40 km) west of Dallas, January 15, 2022. Photo: VCG

 All four people taken hostage in a more than 10-hour standoff at a Texas synagogue have been freed unharmed, police said late Saturday, and their suspected captor is dead.

The hostage siege in the small Texas town of Colleyville - in which the suspect was apparently demanding the release of a convicted terrorist - had sparked an outpouring of concern from US Jewish organizations as well as from the Israeli government.

Colleyville police chief Michael Miller told a news conference that a "rescue team breached the synagogue" Saturday evening and rescued the three remaining hostages being held inside. A first hostage had been released unharmed a few hours earlier.

"The suspect is deceased," Miller told reporters.

FBI Dallas Special Agent Matt DeSarno said the four hostages - who included a much-loved local rabbi, Charlie Cytron-Walker, were not in need of medical attention, would soon be reunited with their families. "He did not harm them in any way," he said.

There were reports from journalists at the scene of a loud explosion and gunshots at the synagogue shortly before the press conference.

Texas Governor Greg Abbott had announced that the remaining hostages were "out alive and safe" at 9:30 pm (0330 Sunday GMT).

That was more than 10 hours after police were alerted to the emergency at the Congregation Beth Israel in Colleyville, some 25 miles (40 kilometers) west of Dallas.

ABC News reported that the hostage-taker was armed and had claimed to have bombs in unknown locations. That was not confirmed by police although Miller said that "bomb techs are clearing the scene."

Quoting a US official briefed on the matter, ABC reported the man was demanding the release of Aafia Siddiqui, who has been dubbed "Lady Qaeda" by US tabloids.

DeSarno told the news conference the suspect had been identified but did not disclose his identity.

The FBI special agent did not confirm the suspect's demands, but said they were "focused on one issue that was not specifically threatening to the Jewish community" - and that he did not believe there was an ongoing threat.

ABC initially said the man claimed to be Siddiqui's brother, but later clarified her brother is in Houston - while other experts said the word the man used in Arabic was more figurative and meant "sister" in the Islamic faith.

Aafia Siddiqui's lawyer said she "has absolutely no involvement" in the hostage situation in a statement to CNN. The lawyer confirmed that the man was not Siddiqui's brother and said she condemned his actions. Siddiqui, a former Pakistani scientist, was in 2010 sentenced by a New York court to 86 years in prison for attempted murder of US officers in Afghanistan. The high-profile case sparked outrage in Pakistan.