Several sources tell ABC News that a hostage scenario is unfolding at a synagogue, Dallas-Fort Worth region, on Saturday.

An armed person claiming to have explosives in unknown places kidnapped a rabbi and three people at the Congregation Beth Israel, according to an ABC News source. It’s unknown how heavily armed the hostage-taker is. The man was carrying bags and claimed to have bombs. Law enforcement doesn’t know whether that’s true, but they’re responding as if it is.

According to a US source informed on the situation, the hostage-taker claims to be the brother of the convicted terrorist Aafia Siddiqui, but officials have yet to establish his identification. According to the official, the suspect is seeking the release of his sister.

According to the source, Siddiqui is being held at Carswell Air Force Base in Fort Worth. She was convicted of attack and attempted murder of a US soldier in 2010 and was sentenced to prison for 86 years for her claimed links to al-Qaida.

According to Colleyville police, there were no injuries among the captives.

A White House source acknowledged to ABC News that the hostage situation is being “closely monitored.” President Joe Biden, according to Jen Psaki, will be kept updated by his senior staff as the situation evolves.

According to a DHS official, Secretary of Homeland Security Alejandro Mayorkas has also been informed on the issue.

The Colleyville Police Department’s SWAT squad rushed to the location about lunchtime Saturday and evacuated residents.

The issue “remains ongoing” as of 3:20 p.m., according to the department’s social media posts. “We ask that you continue to avoid the area.”

The Department of Public Safety is also there on the scene of a “tense hostage scenario,” according to Texas Gov. Greg Abbott.

“They are working with local and federal teams to achieve the best and safest outcome,” Abbott said on Twitter. “I continue to monitor the situation through DPS.”

The Dallas Police Department is increasing patrols at city synagogues and other locations “as a precaution,” stated Dallas Mayor Eric Johnson on Twitter Saturday afternoon. “Police are working with the Jewish Federation and our local, state, and federal partners to monitor any concerns or threats based on the situation in Colleyville,” he added.