KIEV, November 4 (Reuters) - Ukrainian hackers behind recent Kremlin email leaks said on Thursday they planned to release more information taken from accounts linked to senior Russian officials, including to President Vladimir Putin's chief spokesman. A network of Ukrainian hacking groups, called the Cyber Alliance, has been releasing emails they say were sent to one of Putin's top advisers - a bid to disprove Russia's denial it has stoked separatism in eastern Ukraine and played a direct role in the 2-1/2-year-old conflict there. Speaking to Reuters on condition of anonymity, two members of group RUH8, part of Cyber Alliance, said they would not stop their cyber attacks against Russia while the eastern fighting continues. "Our boys are running with guns in trenches, but thank God we are not there. We're sitting at home, in the warm, with keyboards. So how can we betray them?" said one, wearing a hockey mask to disguise his identity. "We live in the 21st century, so possessing information, analysing it and using it in the proper way plays a very big role," he said. Earlier on Thursday Cyber Alliance released a second batch of emails it claimed to have lifted from an account linked to Vladislav Surkov, a Putin aide dubbed the "grey cardinal" because of his behind-the-scenes influence. The RUH8 hacker said they would release more Surkov emails in around a week, adding that they also had some information relating to Kremlin spokesman Dmitry Peskov that they would release at a later stage. He did not give further details. "HELP AND SUPPORT" If the latest email leaks are authentic, they suggest a close relationship between Surkov and separatist officials, as well as detailed Russian plans to stir up further unrest and anti-Ukrainian sentiment in Kiev-controlled territory. A purported email to Surkov from a Russian official, dated April 2015, proposes the formation of a civilian group in Ukraine's Kharkiv region that would aim to "mobilise dissent, criticism of the politics of Kiev authorities" and promote ideas of greater autonomy. Another email from December 2015 contains a list of candidates for leadership positions in rebel-held Luhansk territory and their resumes, reinforcing reports of the Kremlin's close involvement in the internal political affairs of the self-styled breakaway 'republics.' In a February 2016 email, Donetsk separatist leader Alexander Zakharchenko thanks Surkov for his help in building an independent state in Ukraine's eastern Donbass region. "This process would not have been possible without the great help and support that the Donbass receives from the people of Russia, the country's leadership and from you personally," the email said. The press service for Russia's presidential administration did not immediately reply to a request for comment on the authenticity of the emails. Previously it has said that Surkov does not use email. Russia has repeatedly denied accusations from Kiev and NATO that it has played an active role in the separatist crisis and fighting that has killed nearly 10,000 people since 2014. In an article on website Medium, Atlantic Council's Digital Forensic Research Lab said evidence suggested the leaked Surkov emails are authentic, although their volume - there are more than 3,500 - makes it hard to verify each one individually. Reuters was able to verify one email in the second leak, as it was a request for comment that the Reuters Moscow bureau sent to Surkov in June 2015. The RUH8 hacker said he and his colleagues passed on information to Ukrainian security services, when relevant, but said they did not receive any financial or technical support from the Ukrainian state or from any Western countries. "Ukrainian hacking groups have fairly high technical skills and so there is no need for the U.S. or any other NATO country to support us. What's more, it would be quite an extreme foreign policy move from the U.S.," he said.