• Ukraine's top prosecutor said 410 bodies had been found in towns recaptured from retreating Russian forces around Kyiv as part of an investigation into possible war crimes.
• The European Union plans to introduce fresh sanctions against Moscow in the wake of the new reported atrocities.

LONDON — European markets closed higher on Monday as Western powers prepared more sanctions against Russia following allegations of civilian massacres in Ukrainian towns.

The pan-European Stoxx 600 closed up by 0.9% after a cautious morning. Tech stocks gained 2.2% while insurance stocks fell 0.8%.

Ukraine's top prosecutor said 410 bodies had been found in towns recaptured from retreating Russian forces around Kyiv as part of an investigation into possible war crimes, while Ukrainian President Volodymyr Zelenskyy accused Russia of genocide. Russia has denied allegations that its forces killed civilians in Bucha, 23 miles northwest of Kyiv.

The European Union plans to introduce fresh sanctions against Moscow in the wake of the new reported atrocities, with European Council President Charles Michel announcing on Twitter that "further EU sanctions & support are on their way."

Shares in Asia-Pacific finished mostly higher on Monday, with Hong Kong's Hang Seng index leading gains as shares of Chinese tech climbed after a recent signal by Chinese authorities of progress toward resolving an audit dispute, which had threatened U.S.-listed Chinese firms with delisting.

Stateside, the S&P 500 gained on Monday as traders shook off recession fears and bought technology shares that were beaten up in the first quarter.

In terms of individual share price movement in Europe, German takeout company Delivery Hero surged more than 10% after launching a debt financing syndication equal to around $1.55 billion.

At the bottom of the Stoxx 600, Danish shipping giant A.P. Moeller-Maersk slid 5% after announcing that the CEO of subsidiary APM Terminals would retire on June 30.

A stark repricing of bond markets in recent weeks has also been identified as a key driver of stock markets, and Luke Barrs, head of fundamental equity for EMEA at Goldman Sachs Asset Management, told CNBC on Monday that the bond market was serving as a "discounting mechanism."

"If you look at those higher growth, longer term secular themes that we have been very attracted to, clearly those are long duration assets, so any time that interest rates are going higher and discount rate starts to become more significant a bearing on the valuation of those names, so you've seen a little bit of a retrenchment," Barrs told CNBC's "Street Signs Europe."

"We actually think the market has overreacted to some of those concerns, and our view at the moment is that innovation and some of those innovative areas of the market are now oversold."

Subscribe to CNBC PRO for exclusive insights and analysis, and live business day programming from around the world.