A posse of policemen from Bihar arrived in the city on Monday to take over the custody of Mohammad Saikul and Mohammad Nessar, who were arrested on Saturday by New Market police station in connection with murder and abduction cases in Bihar.

The team, headed by the officer-in-charge of Roh police station, in Nawada district, informed officers of the city force that six other criminals, including an alleged murder mastermind, had been hiding in Calcutta for the past few months.

?The murder had been committed by a gang of 12. Five of them have been arrested in Nawada and one in Calcutta. We have specific information that the rest are also hiding here,? said Kishore Kumar, officer-in-charge of Roh police station.

The silver-colour jeep (No. JH10E 0867) of the Bihar police reached New Market thana at 9 am, after having travelled around 450 km. Kumar went straight to the lock-up and identified Saikul and Nessar.

He, however, confirmed that Nessar had no links with Saikul and that a separate case of abduction was pending against him.

According to Kumar, Saikul and his associates had murdered Islam Siddique on April 29, 2004. The mastermind of the killing has been identified as Manazir.

Manazir had been arrested earlier in connection with a murder case and convicted with life-term imprisonment. He has been released recently.

Elaborating on the motive behind the murder, Kumar said: ?Siddique was becoming popular by the day among the people of Maurigram, in Nawada district. Manazir felt threatened by him, especially because he was trying to become chief of the village panchayat.?

On the day of the murder, Manazir, Saikul and 10 others went to Siddique and asked him to join a meeting called by the panchayat.

?Siddique believed what the group said and left for the meeting. He never came back. We later came to know that they had strangulated Siddique. The body was recovered after three days,? the officer recalled.

What had stunned the police the most was the fact that Manazir had buried the body in his mother?s bedroom.

?He had dug up the floor and placed the body under it and covered the spot perfectly,? Kumar said.

?Manazir had also placed a khatiya on the spot. The 80-year-old woman knew about the body, yet she slept on the bed daily. We came to know about the ghastly act after a thorough examination of the floor,? the officer added.

According to him, as soon as the Bihar police started investigating the case and arrested a few accused, Manazir, Saikul and the others fled and took refuge in Calcutta.

?Of the 12 named in the FIR, we have arrested six. We have specific information that the others are in the city,? he said.