Chon Buri police chief Pol Maj Gen Nanthachart Supamongkol told a press conference on Saturday that Nakhon Boonphanit, 25, and Pakapol Khunphraraksa, 27, were arrested at 11am on Friday in Tambon Napa in Muang district.
Police seized a .38 revolver and five rounds of ammunition from them.
The two were accused of robbing lottery ticket vendors Natthathika Padchasuwan, 40, and Em-orn Sirimanoon, 47, at 10.15pm on December 13.
The two were accused of using a pickup truck to block the motorcycle of the sisters on a road in Muang district and snatched their bag, containing 1,000 lottery tickets and Bt40,000 in cash as well as two mobile phones.