Reported anonymous target the Central Bank of Cyprus website with DDoS attacks on 5/5/2016, resulting in 35 minutes of downtime (steps towards confirmation). There are reports that the event, (also) reportedly part of #opicarus, was easily recovered from, and targeted only the website rather than the Bank’s systems. None of this has been reported on mainstream or social media. Even so the event is claimed (primary 5/5/2015 source below) to be a response to an international call by anonymous for a month-long attack against the banking system, launched on May 3rd. Arguably, if there’s anything notable about this, the reported attack on the Central Bank of Cyprus comes as an early target. This follows reported attacks on the Central Bank of Greece website (ref 1, with a note that the site is down at the time of posting).
The following article appears to be the original source, shared through fresh twitter accounts & the /r/unfilter subreddit: https://www.hackread.com/oplcarus-hacktivists-ddos-central-bank-of-cyprus/
Currently sorting through / seeking intel on the specs & sources of the reported attack, its seriousness, local precedent and its politics.
7/5/2016: wot?! : http://www.techworm.net/2016/05/anonymous-operation-opicarus-continues-ddoses-bank-cyprus.html
& there’s also this:
Will be working the RL side of this for the next few days: what kind of hoax is this?
allonan 
i think you should ask a representative of the central bank of cyprus to comment on http://www.hackread.com‘s article