WASHINGTON (AP) - President Donald Trump is calling a fire at a London subway station another attack "by a loser terrorist" and suggesting police there may have missed an opportunity to prevent it. He also says the government should cut off Internet access to extremist groups.

Trump tweeted Friday: "Another attack in London by a loser terrorist. These are sick and demented people who were in the sights of Scotland Yard. Must be proactive!"

He later added: "Loser terrorists must be dealt with in a much tougher manner. The internet is their main recruitment tool which we must cut off & use better!

The London Ambulance Service says 18 people have been taken to hospitals with injuries, thought to be life-threatening.

Scotland Yard said it would not be commenting on Trump's suggestion that police had known of the attacker.

Trump also used the incident to defend his travel ban targeting six mostly Muslim nations.

He tweeted: "The travel ban into the United States should be far larger, tougher and more specific-but stupidly, that would not be politically correct!"

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