Apichart Puangpetch, 42, and Woraphan Ponlamaiwongdee, 44, were captured in separate arrests and charged with possession of explosives. Mr Apichart additionally was charged with illegal possession of military-grade weapons and violating an order from the National Council for Peace and Order.
A source close to the investigation said the two were connected to the Banthat Thong Road bomb attack on Jan 17 in which one PDRC supporter was killed and 39 wounded.
Deputy police chief Pol Gen Somyos Poompanmuang said investigators believed Mr Apichart and Mr Woraphan were in the same network and both supplied hand grenades to several persons for use in violent incidents at pre-coup protest sites.
Pol Gen Somyos said Mr Apichart's arrest came after further investigation into the recent seizure of weapons in Ayutthaya's Wang Noi district. The suspect reportedly confessed to receiving 20 RGD-5 hand grenades from a group of people and distributing them to his accomplices in order to launch attacks against PDRC protesters. He also dumped four grenades into Khlong San Sab.
Mr Woraphan had been summoned for questioning earlier during an investigation into his alleged explosives possession. Police said he later admitted to hiding an M19A2 grenade and two RGD-5s in a rice filed in tambon Koh Chan of Koh Chan in Chon Buri.
Police would not disclose further details on the incidents the suspects might have been involved in, their masterminds or accomplices, he said.
The source said police would soon seek arrest warrants for two bomb throwers in the the Banthat Thong bomb incident.