Convicted murderer Shoaib Sarwar is due to be executed on Feb. 3.
Shirin Dalvi, editor of Avadhnama, has already been released on bail.
In a statement, foreign affairs adviser also says India should not be granted special status in U.N. Security Council.
Private Schools Teachers Association president criticizes decision, saying educators should not be carrying guns.
Police say vaccination drive will continue despite the attack.
U.S. president is first American leader to be invited to the Indian event.