At least 48 people were killed and six more injured in a Russian attack on a village cafe in northeastern Ukraine on Thursday, officials in Kyiv said.

The attack came as Ukrainian President Volodymyr Zelenskyy attended a summit of around 50 European leaders in Spain to drum up support from the country's allies.

Zelenskyy denounced the attack on the store and cafe in the village of Hroza as a "demonstrably brutal Russian crime" and "a completely deliberate act of terrorism."

He urged Western allies to help strengthen Ukraine's air defenses, saying that "Russian terror must be stopped."

"Russia needs this and similar terrorist attacks for only one thing: to make its genocidal aggression the new norm for the whole world," he said.

"Now we are talking with European leaders, in particular, about strengthening our air defense, strengthening our soldiers, giving our country protection from terror. And we will respond to the terrorists," he added.

Zelenskyy also posted an image of a woman kneeling over the body of someone apparently killed in the strike, with other corpses strewn around her, while rescue workers worked nearby.

Presidential Chief of Staff Andrii Yermak and Kharkiv Gov. Oleh Syniehubov said Russian forces shelled a shop and a cafe in the village of Hroza, in the Kharkiv region, around 1 p.m. (10 a.m. GMT)

A 6-year-old boy was among those killed in the attack, Syniehubov said, and one child was also among the wounded.

The village is 30 kilometers (around 20 miles) west of Kupiansk, a frontline town, and is estimated to have had a pre-war population of around 500 people.