India's National Investigation Agency (NIA) says they have evidence that Islamic militants from India and Bangladesh were receiving training in the Myanmar guerrilla bases of the NSCN (Khaplang group).
The NSCN (K) is a separatist group fighting for an independent state for Nagas to be carved out of areas dominated by the ethnic group in India and Myanmar. 
Its 2012 ceasefire with Myanmar authorities remains intact, but its 2000 ceasefire with India has fallen apart and the rebel group has mounted a series of deadly attack on Indian forces in the last two months killing nearly 30 soldiers. 
NIA officials told Mizzima they arrested Nurul Hoque alias Naeem, the chief trainer of the Jamaatul Mujahideen Bangladesh (JMB)  at the Howrah railway station, near Kolkata this week..
NIA officials said that after his arrest on Thursday, Naeem had said he had received advanced training in guerrilla warfare at a base of the National Socialist Council of Nagaland (Khaplang) that is shared by the ULFA, in Myanmar's Sagaing hills.
Hoque claimed that there were other JMB militants who have already received training or were under training in the NSCN-K bases in Myanmar.
The NIA believes the ULFA is the link in the chain between the NSCN based in Myanmar and the Bangladesh radicals.
Before relocating to NSCN-K bases in Myanmar, the ULFA leadership was largely based in Bangladesh.
But they had to leave the country after Bangladesh Prime Minister Sheikh Hasina's government launched a fierce crackdown on anti-Indian rebel groups after she came to power in Jan 2009.
Scores of rebels leaders from India's Northeast were arrested and handed over to India quietly to stand trial.
Ms Hasina's government also went after the Muslim radicals in a big way - and that perhaps forced them to make common cause with northeast Indian rebel groups like the ULFA.