Poland said on Wednesday it had uncovered what could be an attempt to interfere in its presidential election campaign using advertisements on Facebook that may have been financed from abroad, an assertion the social media platform disputed.

Poland’s Prime Minister Donald Tusk says Russian hackers attacked the websites of parties in his ruling coalition just two days before a presidential election.

Poland will hold the first round of voting in its presidential election on Sunday. This is a hotly contested race between two main candidates – one from Civic Platform, the lead party in the ruling Civic Coalition, and the other an independent backed by the main opposition party, Law and Justice (PiS).

Liberal Warsaw Mayor Rafal Trzaskowski and conservative historian Karol Nawrocki are leading candidates in Poland's presidential election, heading into a competitive runoff. Trzaskowski, a pro-European Union advocate,

The national cybersecurity authority, NASK, said it had discovered 'new information operations aimed at destabilizing the electoral process.' Poland is holding its presidential election on Sunday.

Poland said on Wednesday it had uncovered what could be an attempt to interfere in its presidential election campaign using advertisements on Facebook that may have been financed from abroad. European