Nazmul of Meherchandi area in the city was arrested at his house following a statement of Jahangir, a guard of Taher's house in the teacher's quarters.

Police said they have identified a group of five to be the killers, but they have yet to be sure about the motive for the killing.

Jahangir was arrested with a bloodstained pillow and bedcover hours after Taher's body was spotted inside a sewer behind his house early Friday.

A police official said it is too early to reach a conclusion about the murder.

"The investigation so far suggests it was not a killing out of political animosities. We are not ruling out the possibility of the guards committing the murder for money," said a source in the police.

Another police official however said a conflict among teachers of the geology and mining department might have resulted in the murder.

Some sources at RU pointed the finger at the Islami Chhatra Shibir, the student wing of ruling coalition partner Jamaat-e-Islami.

"Apparently, ultimate the benefit of the killing goes to Jamaat and Shibir as Taher had been a stiff roadblocks to the wholesale recruitment of Jamaat men as teachers and employees of the university," said a teacher.

Another teacher said the geology and mining department has no teacher with allegiance to Jamaat, which was the case at economics department before the murder of Prof Yunus on December 24, 2004.

"But soon after Yunus murder, four pro-Jamaat teachers joined the ranks at the economics department," he added.

Meanwhile, the campus yesterday mourned for Taher with teachers and students continuing protest against the ghastly crime. Wearing black badges, they held processions and rallies throughout the day. Academic activities in almost all the departments remained suspended during the strike.

Several hundred members of RU Teachers Association (RUTA) took part in a silent procession in the morning. They demanded security and proper investigation into the murder. They demanded the killers of both Yunus and Taher be brought to justice and dealt out due punishment.

RUTA begins a two-day long work abstention today.

Geology students laid siege to the RU vice-chancellor's house for over an hour. They met VC Prof Altaf Hossain and said if the authorities fail to arrange proper investigation within the next three days, they will go on a tough movement.

Activists of the main opposition-backed Bangladesh Chhatra League ransacked the offices of law, animal husbandry and veterinary science departments while some teachers at those departments were taking classes defying the strike called by BCL.

Chairman of law and justice department Rabiul Islam was reportedly assaulted during the rampage.

SECURITY BREACH AT FEMALE HALL
Further exposing the lax security on the campus, an unidentified youth entered female student hall Tapashi Rabeya in the early hours yesterday.

The students went berserk at the news and damaged the room of hall provost. They also handed over two separate memorandums to the provost and RU administration, protesting the killing of Taher as well as the breach of security at their dormitory.

They demanded identification of the intruder within three days and increase in the number of security guards at the hall.