LONDON — While most U.K. political leaders and media commentators have limited their comments on Tuesday’s Brussels bombings to messages of support and sympathy, a few have used the tragic events as an added justification for Britain to leave the European Union.

On June 23, U.K. voters will get a chance to vote in a referendum on whether to stay in the E.U. or leave it. The argument between those on each side has become increasingly bitter and permeates the debates on every major issue.

It was only a matter of hours before those arguing for a British exit from the E.U. — shortened to “Brexit” in the local media — would point to the attacks in Brussels, the administrative center of the E.U., as another example of an E.U.-inspired failure. Their primary target was the Schengen agreement, which allows passport-free movement between 26 European countries, but not the U.K.

The U.K. Independence Party, which campaigns for an exit from the E.U., led the way in linking the Brussels attacks to Brexit. Its defense spokesman Mike Hookem, who is a Member of the European Parliament in Brussels, said: “(U.K. Prime Minister) David Cameron says we are safer in the E.U. Well, I’m in the heart of the E.U. right now and it does not feel very safe.”

He added: “The fact that terrorists can strike at the heart of the E.U. with apparent ease shows that they are perfectly placed to exploit the lax security situation created by the Schengen agreement and the E.U.’s open-door policies.”

UKIP leader Nigel Farage retweeted a comment made by Allison Pearson, an author and columnist on the Daily Telegraph newspaper, which stated: “Brussels, de facto capital of the EU, is also the jihadist capital of Europe. And the Remainers dare to say we’re safer in the EU! #Brexit.”

Meanwhile another author Tony Parsons, who is a columnist for Rupert Murdoch’s tabloid newspaper the Sun, tweeted: “Thoughts are with the people of Brussels. No nation in the world can protect its citizens without protecting its borders. #VoteLeave #Brexit”