A knifeman brought terror to the heart of London on Wednesday afternoon, with four people, including an armed police officer and his attacker, killed.
England's friendly in Germany is due to go ahead as planned and, as the incident is still unfolding, the FA plans to mark the Westminster attacks on Sunday having spoken to relevant authorities.
"Our thoughts are with all of those who have been affected by this terrible incident," FA chairman Clarke said ahead of the match in Dortmund.
"We will be recognising the bravery of the security services and all those involved at the England v Lithuania match on Sunday."
England face Lithuania in a World Cup qualifier at Wembley on Sunday (5pm).
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