For nearly a week, Middlesbrough has been gripped by a wave of violence that has left residents too intimidated to leave their homes.'This is terrorism,' declared Andy McDonald, the MP for Middlesbrough and Thornaby East as he led growing calls for police to get a grip on the suspected gang violence spiralling out of control.But for locals, postcode gangs have been terrorising the town long before Saturday's fatal A66 crash, running county lines operations, grooming young children and fighting battles over the town's drugs trade. A surge in violence followed the deaths of five young men – four of whom had previous convictions – after they crashed into a police car while driving the wrong way down the A66 at South Bank, near Middlesbrough, killing PCs Matthew Blades and Tom Clough.Since then, two men, aged 31 and 23, have been arrested on suspicion of murder after seven-year-old Valentina Foster and her aunt Natalie McDonald, 34, were killed on Wednesday in a house fire in Grangetown, around one mile from the A66 crash. And on Thursday, a house on Steele Crescent, South Bank, was rammed into by a car and a 39-year-old man was stabbed on Sedgemoor Road, Eston. Police have not yet established if they are all linked to the A66 crash.South Bank, Grangetown and Eston, are all within the TS6 postcode of Middlesbrough, which has long been a hotspot for criminal activity. Thugs in the area are understood to have a long-running rivalry with the neighbouring TS3 postcode, which covers estates such as Thorntree, Brambles Farm, Park End and Berwick Hills.Members of the A66 crash gang are also believed to be linked to criminals convicted of being part of organised county line gangs in the TS3 and TS6 postcodes. Curtis Cremin, pictured holding a huge machete, was jailed for running an organised county drugs line, in TS6 and TS3. It is understood he has links to the A66 gang Louie Leadbeater (right), who was jailed for three years for his involvement in a county lines gang in Middlesbrough, is pictured with Cole Worthy (left), one of the five who died in the A66 crash