More than 10,000 people died across Europe during an eight-day heatwave from June 20 to 28, according to a report released Sunday by EuroMOMO, a monitoring organization jointly operated by the European Union and the World Health Organization. The report stated that most of the deaths occurred among people aged 65 and older, primarily due to heatstroke and heat-induced cardiac or respiratory failure.

EuroMOMO official and Danish Statens Serum Institute chief physician Lasse Vestergaard told Reuters that the deaths were directly caused by extreme heat, calling the number unusually high for such a short period. The report did not specify country-by-country figures but noted that a large share of the deaths occurred in France and Belgium. Official data indicate that EU countries have been recording an average of 500 heat-related deaths per week for the past eight weeks.

European scientists attributed the June heatwave to human-induced climate change and warned that similar extreme heat events are likely to recur in the coming years.