West Midlands Police say the motive for the attack is unclear. The man has been identified and his family are being informed.
Cockshut Hill and the surrounding area is likely to remain closed until tomorrow.
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Ronald suffers mental health issues and police have advised anyone who sees him not to approach directly.
Police launched a murder inquiry after they were called to an address in the Sneinton area of the city just after 6am yesterday.
Kal Yafai, Birmingham’s first World Champion, dominated Luis Concepcion to be crowned the WBA Super-Flyweight champion last night.