BRUSSELS (AP) — The leaders of Belgium and the Czech Republic are warning their European Union partners to take urgent action to prevent Russian interference in June’s Europe-wide elections, after the two countries’ intelligence services uncovered evidence of attempts to bribe EU lawmakers.

“We simply cannot allow Russia to get away with such a blatant attack on our democratic institutions and principles,” Belgian Prime Minister Alexander De Croo and his Czech counterpart Peter Fiala said in a letter, as EU leaders held a summit in Brussels on Thursday.

“We must arm ourselves against this, both at national and European level,” they wrote.

Last week, with campaigning for the June 6-9 starting to gather momentum, De Croo said that Belgium’s intelligence service has confirmed the existence of a network trying to undermine European support for Ukraine in its war against Russia.