Grenades, guns and drugs were found by police in a series of dawn raids across Liverpool and Manchester.
Officers carried out eight raids this morning (Wednesday) and arrested 12 people across the areas.
Detectives searched properties on Parkview Road, Camelford road, in Gillmoss and Parkhill Road in Dingle.
Properties on Falside Walk, Pirie Walk, Warwick Road and Medlock Road in Manchester were also searched, reports the Manchester Evening News.
Nine men - aged between 22 and 54 - and three women - aged 25, 29, and 34 - were detained.
They are all being held in custody on suspicion of conspiracy to supply controlled drugs, money laundering and firearms offences.
Inspector Anthony Norman, from Greater Manchester Police, Serious and Organised Crime Group, said: “Thanks to the dedication and professionalism of our officers, we have been able to apprehend a large group of individuals this morning.
“I’d like to thank colleagues in Merseyside who have assisted us with today’s operation.
“Our enquiries remain ongoing and I’d encourage anyone with information to contact us.
“The best weapon we have against drug dealers is the wider community, on whom we rely to help us catch and prosecute those who seek to profit from the sale of narcotics.”
Anyone with information should contact police on 101 or the independent charity Crimestoppers, anonymously, on 0800 555 111
