London police said on Tuesday they are reviewing their plans for protecting public events over the festive period after Russia's ambassador was killed in Ankara and a truck plowed into people at a Christmas market in Berlin. 

"The Metropolitan Police has detailed plans for protecting public events over the Christmas and New Year period," police said in a statement. 

"As a matter of routine, as a precaution, we review our plans after attacks overseas, and we are doing so at present following the awful incidents in Berlin and Ankara last night."