killing eight. just hours later, in the netherlands, another attack, a man stabbed several people, on a shopping street in the hague before running off mass stabbings in two cities europe's police on high alert tonight. police say the man was 28-year-old usman chan from the english midlands who just served six years in jail, for islamist terrorism. he had been wearing an electronic tag since his release last year. police say he had been at a conference, on prisoner rehabilitation when he began his rampage and they believe he acted alone. lester bill neely in london richard engel is also in london. richard, these bear the hallmarks of isis inspired attacks we have seen in the past, the knive, the european cities, the fake suicide bomb, and why now and could this be the start of something. >> reporter: lester, it could be the start of something and they do bear all of the isis