Two teenagers have been arrested in the United Kingdom’s Manchester city as part of the investigation into a siege of a synagogue in Colleyville city of Texas in the United States, The Guardian reported on Monday.

The incident took place on Saturday at the Congregation of Beth Israel. A gunman initially took four people hostage, including the rabbi at the synagogue. The gunman released one of the hostages unharmed and later three others were freed by the US’ Federal Bureau of Investigation.

“CTP [counter terror policing] North West and CTP International operations continues to assist the investigation being led by the US authorities, and police forces in the region are liaising with local communities to put in place any measures to provide further reassurance,” the Greater Manchester Police said in a statement, according to The Guardian.

The age and gender of the two teenagers were not revealed immediately. They have been taken into custody for questioning.

Meanwhile, the Federal Bureau of Investigation has identified the gunman as Malik Faisal Akram from the United Kingdom, the BBC reported. He was shot dead by the police during the standoff.

Akram’s brother Gulbar confirmed the death. He also said his brother had been suffering from mental health issues.

Akram had landed in the United States’ JFK International airport two weeks ago, the police said.

At the synagogue, the man was heard seeking the release of Aafia Siddiqui, a Pakistani neuroscientist who is allegedly linked to the terrorist outfit Al-Qaeda. Siddiqui is reportedly lodged in a prison in Texas.

In 2010, Siddiqui was sentenced to 86 years of imprisonment for assaulting and shooting at United States Army officers while being detained in Afghanistan.

United States President Joe Biden confirmed that Akram was seeking Siddique’s release, the BBC reported. He also said that the attacker had probably purchased arms from the United States.

Biden on Saturday had said that he was grateful for the work of law enforcement officers. He also said that the administration will stand against anti-Semitism and the rise of extremism in the country.

Currently, the counter-terrorism police in London have been communicating with their US counterparts as the Federal Bureau of Investigation confirmed an active inquiry, The Guardian reported. The investigative agency suspects that Akram had acted alone.