Police sources said 37 of the accused named in the FIRs lodged in connection with the violence belonged to one group. One of those killed and four of the critically injured belonged to the rival group.

The second victim, identified as Ved Prakash, who succumbed to his injuries in hospital Friday, was passing by on a scooter and suffered three bullet injuries.

Sources said one of the rival groups is led by former BSP MP Dawood Ahmad and the other by Sayyad Taki Abbas alias Doctor, who is among the critically injured.

Taki Abbas had organised the majlis at Deputy Ka Maqbara on Wednesday night. Suleman alias Shanu, who was killed in the firing, and those critically injured are close to him.

Those named in the FIR as accused are mostly relatives and associates of Ahmad.

Asked if rivalry between the two groups was behind the trouble, ADG of Police (Law and Order) Arun Kumar said police knew the reasons but did not elaborate.

Lucknow Range DIG Navniet Sakera said personal issues could be behind the firing and added the incident was being investigated.

Police sources said the rivalry between Ahmad and Taki Abbas goes back about six years. Until then, Ahmad apparently had a monopoly of the real estate business in the area. But Abbas bought a plot in Golaganj area and built residential flats. Later, he built another residential complex in the same area. Two more buildings are being built near Wazirganj police station.

A senior official said there were instances when Abbas bought certain properties which Ahmad was keen to acquire. As Abbas’s business grew, the rivalry between them also increased, although it never led to violence.

Sources said that on the night of the majlis, Ahmad’s cousin Mohammad Sajid went to the venue and asked the volume of the loudspeaker to be reduced, saying the speeches were objectionable. But no one apparently paid heed to him.

Around 9 pm, power supply at the maqbara was snapped. Javed Hussain of Mashaganj area said his brother Abbas Rizvi walked out with Taki Abbas and others to check on the power supply when Sajid and six of his associates allegedly fired at them.

Rizvi and Suleman were shot from a pointblank range. Witnesses said Taki Abbas ran inside to escape but suffered bullet wounds in his thigh and right hand. Two of his associates were also shot from pointblank range.