A Bangladeshi minister on Tuesday blamed explosives smuggled from India and militants operating "from across the border" behind violence in his country.
The government had been able to plug the sources, "but not 100 per cent," State Minister for Home Lutfozzaman Babar was reported telling the media.
The Bangladesh government has been routinely alleging "elements from across the border", including militants, political activists and dissidents who, it says, have taken shelter in India and are engaged in "anti-Bangladesh activities."
Bangladesh has given lists of such persons and organisations to counter India's list of militants from northeastern states running camps in Bangladesh.
Babar was briefing media on investigations into nationwide explosions that took place on August 17 last year, but refused to disclose the names of the 'patrons' of the militants who were under trial "without adequate proof".
According to media reports about the trials of the top leadership of the proscribed Jama'atul Mujahideen Bangladesh (JMB), the Islamist militants have claimed in open courts their "connections" with members of the ruling Bangladesh Nationalist Party (BNP) and coalition partner Jamaat-e-Islami (JEI).
However, the minister dismissed such claims as accusations "out of personal grudge".
A total of 698 people have been arrested so far in connection with 154 cases filed for the blasts on August 17 along with 87 other cases for another series of explosions that took place later.
Police submitted a charge sheet in 183 cases while 56 cases are under investigation. Trial of 17 cases has been completed, trial of 81 cases is going on and final report has been submitted in another case, according to Babar.
Fighting militancy is a continuous process and it is going on with the government arresting some of the "top militant leaders", he said.
He claimed to have destroyed the militants "ideologically" through motivational programmes across the country.