They have been arrested on the charge of attacking political leaders, candidates and cadres ahead of the elections.
Of them, 600 were associated with Biplav-led Maoist, 13 reportedly with CK Raut group and remaining 344 belonged to some other political parties, The Himalyan Times reported.
Spokesperson for the Nepal Police Manoj Neupane assured that the police was committed to ensure the security and safety for candidates and voters so as to make the elections successful.
"The Nepal Police has deputed booth security squads, mobile teams and security in plain clothes for the purpose of election security," The Himalyan Times quoted the police official as saying.
The security personnel, who were assigned for the first phase of elections, have been sent to the districts where the second phase of elections to the House of Representatives and State Assemblies is scheduled to take place on Thursday.
The security has been strengthened in view of the second phase of polls with additional security measures.
Nepal also closed its border points with India for three days from Tuesday mid-night ahead of elections.
A 65 percent voter turnout was recorded in the first phase of the elections. (ANI)