Hackers attacked some of the Czech Republic’s main news websites on Monday, Reuters reported. Executives from three of the Central European state’s most widely read online titles – www.ihned.cz, www.idnes.cz and www.novinky.cz – said their websites had been disrupted. There was no immediate information on who was responsible. The hackers flooded the websites with digital requests, overwhelming their systems – a common tactic known as a distributed denial of service attack. Hackers have also targeted dozens of computer systems at government agencies in the Czech Republic, Ireland, Romania and other European counties, exploiting a security flaw in Adobe Systems Inc’s ADBE.O software, researchers said.