STOCKHOLM/BRUSSELS (Reuters) - Swedish teenage activist Greta Thunberg urged European politicians on Friday to focus on a climate crisis instead of "bickering", as children walked out of classes around the world to back her demands for urgent action to curb carbon emissions.

Thunberg, 16, said the threat of societal breakdown posed by runaway climate change should overshadow every other campaign issue in the European Union's parliamentary elections this week.