Police staged an operation in Moyale Town and arrested two robbery with violence suspects following complaints of increased armed robberies.
The team recovered a pistol and cash believed to have been robbed from unknown victims.
Elsewhere in the same region, two other suspects were arrested in the Hilo mining site and a rifle loaded with six live rounds, police said.
Moyale is on the Kenya-Ethiopia border and some suspects stage attacks on both sides before escaping.
Officers from the DCI's Transnational Organized Crime Unit detectives staged the operation in the Sessi area of Moyale, leading to the recovery of the pistol, Sh83,000 and 169,995 Ethiopian Birr.
Police said the recovery shows the suspects were operating in Ethiopia and Kenya. The two were on a motorcycle when they were stopped, police said.
Meanwhile, two other suspects involved in a botched robbery were arrested at the Hilo mining site still in Moyale, and a rifle loaded with six live rounds was seized by the police from Dabel station.
The two suspects were cornered at a shop within the Hilo gold mine after the shopkeeper made a distress call, police said.
The two will be arraigned on Monday 19 where appropriate charges will be preferred, police said.
The area has been experiencing a rise in armed crime amid operations to address the trend.
Gangs are sometimes used to man some of the gold mining sites complicating the situation there.
This is also the main route human smugglers use from Eritrea and Ethiopia.
The smugglers are at times armed making the war on the crime complex.
Dozens of victims are usually intercepted on the route on a weekly basis, which has prompted the government to deploy multi-agency teams there to address the menace.
Most victims use Kenya as a transit route to other places like South Africa and the Middle East for jobs.
This has prompted among others the deployment of teams led by the Transnational Organised Crime Unit in the area and other main border towns.
