A cyber rapid-response team (CRRT) is being deployed across Europe, after a call for help from Ukraine.

The newly formed team of eight to 12 experts, from Lithuania, Croatia, Poland, Estonia, Romania, and the Netherlands, has committed to help defend Ukraine from cyber-attacks - remotely and on site in the country.

An official warned attacks were likely.

"We can see that cyber-measures are an important part of Russia's hybrid toolkit," the CRRT official said.

It comes after the UK and the US blamed Russia for cyber-attacks earlier this month that temporarily took a small number of Ukrainian banking and government websites offline.

The Lithuanian Ministry of Defence tweeted: "In response to Ukraine request, [we] are activating [a] Lithuanian-led cyber rapid-response team, which will help Ukrainian institutions to cope with growing cyber-threats. #StandWithUkraine."

CRRTs are a European Union initiative to deepen defence and co-operation between member states.

They are said to be equipped with commonly developed cyber-toolkits designed to detect, recognise and mitigate cyber-threats.

An official said the team was "composed of different cyber-expertise, such as incident response, forensics, vulnerability assessment, to be able to react to a variety of scenarios".

Russia has previously been accused of so-called hybrid warfare, combining cyber-attacks with traditional military activity, in Georgia and Crimea.

The EU and Ukraine blamed Russia after thousands of people in multiple cities in Ukraine experienced power cuts, in 2015 and 2016, when hackers temporarily shut off electricity substations.

The US, UK and EU also blamed it for the hugely disruptive NotPetya wiper attack.

Experts say about 2,000 NotPetya attacks were launched in 2017, mainly aimed at Ukraine but the malicious software spread globally, causing billions of dollars of damage to computer systems across Europe, Asia, and the Americas.

Moscow denies being behind the attack, calling such claims "Russophobic".