The Uttaranchal police on Monday arrested a Lashkar-e-Tayiba militant in Dehradun.
The arrest came close on the heels of an 'encounter' on Saturday, when the police shot dead three and arrested two LeT militants here.
Delhi Joint Commissioner of Police (special cell) Karnal Singh said on Tuesday that the accused, Mohammad Iftikar Ehsan, has been brought to Delhi for questioning.
Ehsan, who hails from Bihar, was studying in a biotechnology institute in Uttaranchal, Singh said.
Interrogation of the two militants arrested on Saturday had revealed that they had planned to carry out a suicide attack on the Indian Military Academy in Dehradun.
They had also carried out a recce in Bangalore. Their target -- software companies.
Ehsan is suspected to have provided information about IMA to his colleagues hiding in Delhi, police sources said.
Police teams have also left for Patna, where the group is suspected to have established another base.