A murder investigation is under way after a teenage boy was fatally stabbed in east London.Police were called to Stellman Close, Hackney at around 4pm on Tuesday.Officers attended the scene to discover the victim - believed to be aged 15 - with stab wounds.Despite the best efforts of emergency services, he was sadly pronounced dead at the scene.The attacker is believed to have run away from the scene.A Metropolitan Police spokesman said: “We are in the process of informing his next of kin.”He is the second teenager to be killed in London within 48 hours.