Terming the decision as "undemocratic", Mr Modi alleged "it shows that the state government does not want the truth about the Kishtwar violence to come out."
"Landed in Hyderabad. Heard that Shri Arun Jaitley and other Opposition leaders are not allowed to go to Kishtwar. This is undemocratic," Mr Modi tweeted.
"Stopping Opposition leaders in this manner shows that the Government does not want the truth about the Kishtwar violence to come out," the BJP election campaign chief wrote on Twitter.
J&K Chief Minister Omar Abdullah has said politicians and separatist leaders will not be allowed to travel to Kishtwar in the Jammu region.
Kishtwar remained curfew-bound for the third consecutive day today after communal violence broke out in the city on Friday.
Mr Jaitley was detained as he arrived at the Jammu airport on his way to Kishtwar.
Curfew was today clamped in three more districts of Udhampur, Samba and Kathua in Jammu region and Army staged flag marches as tension prevailed following outbreak of communal violence in Kishtwar.