Deputy Inspector General of police Harinarayanachari Mishra told reporters that those arrested included two alleged arms dealers.
They were identified as Amarjit Singh Bhatia, resident of Dhar, and Virendra Singh, resident of Barwani.
The other accused were allegedly trying to buy firearms from the duo, he said.
Police recovered 19 firearms including country-made revolvers and pistols besides cartridges, he said, adding that further probe was on.
Assembly elections will be held in Madhya Pradesh on November 28.