Garissa County Commissioner Mohammed Maalim said they have been on high alert after their intelligence officer received threat alerts.
“The police impounded two pistols, three hand grenades and 84 rounds of ammunitions at Amuma border point today,” Maalim told journalists in Garissa town.
The vehicle which had 10 people on board was stopped by a combination of rural border patrol unit, administration and regular.
“Four of the passengers escaped as police were taking control of the land cruiser with six of them being arrested,” said Maalim.
The group was reportedly headed to Hagadera Refugee Camp when the recovery was made. North Eastern police boss Philip Tuimur said the suspects were escorted to the Dadaab Refugee Camp for further interrogation.
Other officers said there were reports the weapons and grenades were to be used in Garissa town for an attack.
Garissa has been the target of attacks by suspected terrorists who ambush and kill security agents, with up to ten dying in similar incidents in the past months.