COLLEYVILLE, Texas (AP) — Texas Gov. Greg Abbott tweeted that all hostages are safe after Saturday's standoff inside a Dallas-area synagogue.

"Prayers answered. All hostages are out alive and safe," Abbott tweeted Saturday night.

Abbott's tweet came not long after a loud bang and what sounded like gunfire was heard coming from the synagogue. Details of the rescue were not immediately clear.

At least four hostages were initially believed to be inside the synagogue, according to two law enforcement officials who were not authorized to discuss the investigation and who spoke to The Associated Press on the condition of anonymity. The synagogue's rabbi was believed to be among the hostages, one of the officials said.

Authorities are still trying to discern a precise motive for the attack. The hostage-taker was heard demanding the release of Aafia Siddiqui, a Pakistani neuroscientist suspected of having ties to al-Qaida, who was convicted of trying to kill U.S. military officers while in custody in Afghanistan, one of the law enforcement officials said. Siddiqui is in federal prison in Texas.

The officials said investigators have not positively identified the man and cautioned that the information was based on a preliminary investigation as the situation was still rapidly developing.

FBI Dallas spokeswoman Katie Chaumont said an FBI SWAT team was also at the scene and that crisis negotiators had been communicating with someone inside the synagogue. But she could not say whether the person was armed and she declined to describe what the person had said to authorities, citing operational sensitivity.

Police were first called to the synagogue around 11 a.m. and people were evacuated from the surrounding neighborhood soon after that, Chaumont said.

There have been no reported injuries, Chaumont said, and authorities weren't certain how many people were in the synagogue.

“It’s an evolving situation, and we have a lot of law enforcement personnel on scene,” Chaumont said.

Law enforcement shut down access to the roads surrounding the synagogue Saturday afternoon.

The services were being livestreamed on the synagogue's Facebook page for a time. The Fort Worth Star-Telegram reported that an angry man could be heard ranting and talking about religion at times during the livestream, which didn't show what was happening inside the synagogue.

Shortly before 2 p.m., the man said, “You got to do something. I don’t want to see this guy dead.” Moments later, the feed cut out.

The man, who used profanities, repeatedly mentioned his sister, Islam and that he thought he was going to die, the Star-Telegram reported.

Colleyville, a community of about 26,000 people, is about 15 miles northeast of Fort Worth.