At least one person is dead after a van hit a crowd of Muslim worshippers in London, according to police.
Prime Minister Theresa May's office says she has been told about the crash in north London in which a vehicle struck several pedestrians.
May described the crash early Monday morning as a "terrible incident."
She said, "All my thoughts are with those who have been injured, their loved ones and the emergency services on the scene."
The leader of the opposition Labour Party Jeremy Corbyn also tweeted about the crash.
Police have said the crash caused several casualties and that one person has been arrested.
The Muslim Council says a van has "run over worshippers" leaving the Finsbury Park mosque.
Police earlier said a vehicle had struck several pedestrians early Monday morning and one person had been arrested.
The council tweeted that its prayers were with the victims. People had been attending mosques in the area as part of the Muslim holy month of Ramadan.
Transportation officials said roads were being closed in the area. Many police cars and ambulances were responding. Further details were not immediately available.