RAJSHAHI, Nov 18: A group of hired murderers took part in a killing mission to hack Professor AKM Shafiul Islam Lilon to death on Saturday, according to investigators.
"The mission was over, they fled the spot by climbing over a nearby wall before anyone could follow them," a high official of Rajshahi Metropolitan Police (RMP) told  the Daily Observer on Tuesday.
At least six young men were suspected to be involved in the gruesome murder of the Rajshahi University teacher, the official added, claiming to have found some clues after talking to several witnesses.
The six young men first surrounded Prof Shafiul in front of his house and forced him to step towards a bush there.   "The killers took position behind a bush in a dark, shadowy place," the RMP official revealed.
Armed assailants hacked the RU teacher to death in the Chouddopai area in Rajshahi city. He succumbed to injuries while undergoing treatment at the Rajshahi Medical College Hospital, the police official further said.
"The handle of the machete that we recovered from the spot was wrapped with nylon so that it did not slip during the hacking. Moreover, there was no finger print on the handle," said an officer of the Detective Branch of Rajshahi police.
Another high ranking official from the RMP headquarters said they had been following two routes for the investigation.  "We have done the forensic test already. Using technology, we have got some other sensational information. For instance, we have learned that one of the killers had been using his mobile phone in an unusual manner at the crime scene."
He also said: "We have prepared a list of suspects comprising numbers that had made phone calls before and after the murder to some fixed numbers over a 20-minute period." Analysing the phone calls, witness statements and the way the killers behaved, police guessed that they were not local people.
The official also said: "The most sensational part is that some of the suspected mobile phone numbers are registered under names of the people involved with the politics of Jamaat-e-Islami and its student wing Chhatra Shibir."
He said the murder scene details suggested that it was a well-planned operation which could be termed a 'silent killing.' That, he said, was one of the major directions that the investigation was heading to.
"Additionally, we are also trying to find out whether any conflicts, including Prof Shafiul's political affiliations, could be behind the murder," he said.
Meanwhile, police on Tuesday showed 11 people arrested in connection with the case and sought seven days' remand for each.
Alamgir Hossain, officer-in-charge of Motihar Police Station, said all of the killer-suspects had cases filed against their names and were involved in sabotage and inciting violence in the area in the past.
Islamia College Principal and Jamaat leader Humayun Kabir, madrasa teacher Fazlul Haque, Abdul Al Mahmud, village doctor Mosharraf Hossain Pintu, Moshiur Rahman, Hasibur Rahman, Jinnat Ali, Saifuddin, Rezaul Karim, Arif and Sagor were the 11 shown arrested on Monday. Earlier, police detained 34 people during special drives over the last two days in connection with the murder.