A shooter at the Jewish museum in Brussels killed four people on Saturday in an attack that has Jewish communities across Belgium on high alert.

Security has been heightened at Jewish sites throughout Belgium, the Wall Street Journal reports, including the diamond quarter in Antwerp.

The Antwerp World Diamond Centre (AWDC) and the Israel Diamond Exchange (IDE) both released statements condemning the attacks and offering condolences to the victims and their families.

“On behalf of the Antwerp diamond sector, we would like to express our heartfelt condolences to the victims and their families. The diamond sector will hold a minute of silence today at 12 o’clock,” said AWDC CEO Ari Epstein in a statement.

“The members and the board of the Israel Diamond Exchange are shocked and appalled by the horrific terrorist attack that claimed the innocent lives of four visitors to the museum on Saturday. We send our heartfelt condolences to the families of the victims and call on the Belgian authorities to spare no effort in apprehending and punishing the perpetrators of this cowardly attack,” said IDE president Shmuel Schnitzer in a statement. 

JCK