Militants fighting Indian rule in the country's northeast have killed 34 people in bombings and shootouts as the nation tightens security on the eve of Independence Day celebrations.
In two incidents in the volatile state of Tripura, armed militants fired indiscriminately, killing 11 people in Kamal Nagar and 14 in Krishnapura village.
A remote-controlled bomb earlier went off just as a bus was crossing a bridge in neighbouring Manipur, killing six passengers and wounding 13, a police spokeswoman said.
"The incident appears to be connected with Independence Day," she told Reuters from the state capital, Imphal, about eight kilometres [five miles] from the site of the attack.
"Unidentified tribal militants from either the All Tripura Tiger Force (ATTF) or the Nationalist Liberation Front of Tripura (NLFT) struck at Kamal Nagar and Krishnapura," a police spokesman said.
The NLFT and the ATTF are outlawed rebel groups who are fighting for a separate homeland for tribal people. Both have called for a boycott of Friday's Independence Day celebrations.
Hundreds of thousands of soldiers, police and commandos are on high alert across India, including in the disputed region of Kashmir, to ward off militant strikes.
Kashmir's main separatist alliance, the All Parties Hurriyat (Freedom) Conference, which seeks implementation of UN resolutions to determine the future of the Himalayan territory, has called for a strike to protest against the ceremonies.