Northumbria Police were called to Dodds Lane in the early hours of Sunday, August 23, to reports of an assault and that a male inside the Alnwick property appeared to have a firearm.
Witnesses say both armed officers and police dogs were at the scene throughout the morning.
Two men have been arrested and remain in police custody.
A Northumbria Police spokesperson said: “Shortly before 4am today (Sunday) we received a report of an assault at an address within Dodds Lane, Alnwick.
“The persons are known to each other.
“It was also reported that a male was present within the address with what appeared to be a firearm.
“Two men, aged 32 and 25, have both been arrested on suspicion of possessing a firearm and remain in police custody.
“Police are currently searching the property.”