Teachers and pupils in all 25 European Union countries observed a minute's silence on Tuesday in memory of the Beslan school massacre in southern Russia.
More than 330 people were killed last week, half of them children, in a terrorist siege.
Schools throughout Britain joined government departments in stopping work at 11am as a mark of sympathy.
Among them was Bingley grammar in West Yorkshire. John Patterson, head, said the silence left a sombre mood in the school for the rest of the day.
"Pupils are often deeply affected by incidents like this. Before the minute's silence I asked teachers to take a few minutes to reflect with the children on what had happened," he said.
The siege began on September 1, as pupils and staff were celebrating the start of the new academic year. It ended tragically three days later when bombs rigged by the hostage-takers exploded inside the school gymnasium, and Russian troops were forced to move in.
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