GUWAHATI, August 11: A virtually open Assam-Bangladesh border and a favourable demographic pattern along the border areas has encouraged the Pakistan's Inter-Services Intelligence (ISI) agents to use Assam as a route to enter the country. This fact came to light after the arrest of four important ISI men in the city recently, police sources said. They said during interrogation of the four arrested ISI men - Md Fasih Ullah and Md Javed Wakhar of Pakistan, Maulana Hafiz Md Akram Mallik of Kashmir and Qari Salim Ahmed of Uttar Pradesh - the police came to know that those people came to Dhaka from Pakistan and entered Assam by crossing the Kuchiara river through Karimganj. They paid an amount of Rs 200 each to Border Security Force (BSF) personnel manning the area through one middleman to enter Assam safely. Police sources revealed that among the arrested ISI men, Qari Salim Ahmed came to Assam at least on four or five occasions in the past through the Karimganj border and no security personnel intercepted him at the border. The main aim of the Pakistani nationals during the present trip through Assam was to look out for a safe route to enter the country through Assam. Security along the international border in the western sector has become tight after the war at Kargil, making it almost impossible for the ISI men to sneak in through the original routes. As Qari Salim knew the routes through Assam, the Pakistani nationals came along with him, sources added. The ISI men were also scheduled to proceed to Kashmir from Assam to trigger off blasts on the Manali-Leh highway to cut off supply lines of Indian Army personnel fighting in Kargil. The sources said that Qari Salim Ahmed is one of the most dreaded militants of the militant outfit Harkat-ul-Mujahideen and he took a number of youths in batches to Pakistan for training through the Assam-Bangladesh route currently being used by ISI agents. During interrogation, the police came to know that all the people taken from India to Pakistan by Harkat-ul-Mujahideen were first taken to Karachi. They were imparted training in handling of arms and explosives in the camps located in Pakistan Occupied Kashmir. All the ISI men nabbed by the police are experts in handling explosives. Police sources said the arrest of Qari Salim was considered by the government as a prize catch as he was wanted in connection with a series of blasts in Delhi three years back. He was also wanted for a blast in Modinagar in Uttar Pradesh and he was involved in taking a number of youths from different parts of the country to Pakistan for training. After the arrests of the ISI men, the police managed to nab as many as 26 ultras belonging to the Harkat-ul-Mujahideen in different parts of the state. The police earlier nabbed a number of militants of Islamic militant outfits but it was for the first time that activists of Harkat-ul-Mujahideen were arrested in the state. The head office of Harkat-ul-Mujahideen is in Karachi and Fazlur Rahman Khalil is the Amir (head) of the outfit. The 'Naib Amir' of the outfit in India is Master Fakruddin alias Akram Master of Goalpara. According to information available with the police, Fakruddin is now in Pakistan. On the basis of the interrogation reports of the arrested ISI men, Nalbari police nabbed a hardcore militant of the Islamic militant outfit Harkat Ul Jehad-Nurul Amin. Police said that Nurul, who was trained in Bangladesh, was involved in the kidnapping of a few foreign tourists in Delhi in 1994. He is now being questioned by security agencies, they said.