However, the whereabouts of Amritpal and his associate Papalpreet Singh remain unknown.
Gang member Lucky has taken responsibility for the murder, said Bhara.
As per preliminary information, constable Reetesh Ranjan fired at his colleagues with his service weapon, an AK-47 rifle, the official said.
After receiving the PM, Thackeray left for Mumbai, state government officials said.
The Supreme Court is scheduled to hear on Monday a plea on the recent breach in Prime Minister Narendra Modi's security in Punjab.
A bench headed by Chief Justice Dipak Misra also issued a notice to the Uttar Pradesh government on the plea filed by Samiuddin, who was allegedly brutally assaulted by the mob in the incident, seeking an independent Special Investigation Team probe into the incident and transfer of investigation and the subsequent trial outside the state.
Union Home Secretary Ajay Kumar Bhalla may have a video conference with West Bengal's Chief Secretary Alapan Bandyopadhyay and Director General of Police Virendra on Friday evening after they conveyed their inability to travel to the national capital, officials said.
Thirteen people were killed and over 70 others injured in the suicide blast which had targeted police officials.
One of the slain terrorists was involved in the killing of police constable Reyaz Ahmad earlier this month, a police spokesman said.
After hearing the case, the chief justice reserved the judgment without giving a date for its announcement.
His father Prakash Singh, who is known for introducing several police reforms and has been awarded Padma Shri as well, had served as the BSF DG from 1993-94.
"The five terrorists killed at Gulshan (cafe) were JMB members. The police had their details and been looking for them for a while," Inspector General of Police AKM Shahidul Haque told media persons.
