At 9.40 a.m., armed police were called to Clarendon Road in Hove in response to reports of a man with a firearm.
The suspects, a 28-year-old man from Worthing and a 41-year-old man from Brighton, were both arrested and remain in police custody on suspicion of possessing a firearm without a certificate.
This is believed to be an isolated incident that does not pose a wider risk to the community,” a Sussex police spokesman said.
The road was closed for several hours due to a police cordon.