Prime Minister David Cameron has tweeted:
I'm appalled by the murder of a Palestinian teenager. The loss of four boys this week is a terrible reminder of the need for lasting peace.
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The report also said that many graduates do not even see a 'earnings premium' from their years at university.
The country's counter-terrorism forces have regained control of the facility.
The commissioner of the Metropolitan Police has said he cannot promise the public an attack will not take place.