"The investigation is positive and there are signs that we are on the right track," Nisar said. "We will get to who ever was behind this act," he added.
Nisar requested that this important investigation is not rushed.
Earlier, the interior minister chaired a high-level meeting at the Rangers Headquarters to review the overall law and order situation in the city and the rest of Sindh province.
The interior minister was briefed about the progress in the investigation of the Safoora incident and other high-profile target killings in the city.
Nisar appreciated the Rangers' role in curbing target killings and said that terrorists involved in recent activities will be brought to justice as the investigations are based on concrete leads, a Rangers spokesperson said.
The interior minister also paid a visit to Yadgar-e-Shuhada and offered fateha.
Speaking at the press conference, Nisar said that so far10,000 intelligence based operations have taken place and many operations were done through police and civil armed forces.
"Ever since the National Action Plan (NAP) commenced, more that 3,000 intelligence based operations have taken place," he added. "There has been an improvement in the overall situation of Pakistan but the war against terrorism is ongoing".
The interior minister also said that the war against terrorism is not an easy war. He added that Pakistan has been a victim of this war since 14 years after 2001.
"2009,2010 and 2011 were intense years when it comes to terrorism and our government tried for the first time to find a cure for this," Nisar said. "Take a look at terrorism in June 2013 and compare it with terrorism now...today weeks pass by and no blasts occur," he added.
He further added that intelligence agencies, police and security have worked hard ever since the operation began.
Nisar arrived in Karachi on a one-day visit to get a detailed briefing regarding Wednesday's terrorist attack on a bus carrying members of the Ismaili community near Safoora Goth in which 45 people were killed and eight others were injured.
The meeting was attended by Director General (DG) Rangers Major General Bilal Akbar, Chief Secretary Sindh, Home Secretary, Sindh Police Inspector General (IG) Ghulam Haider Jamali, Additional Inspector General (IG) Sindh Police Ghulam Qadir Thebo, and other senior officials.
Nisar also met Sindh Chief Minister Qaim Ali Shah and Sindh Governor Dr Ishratul Ibad at the Chief Minister House and Governor House respectively. He is also scheduled to meet the leader of Ismaili community Sultan Ali Allana during his visit.
The interior minister's absence at an apex committee meeting last week was conspicuous, as the high-level huddle was chaired by the Chief of Army Staff (COAS) Gen Raheel Sharif and attended by high-level civil and military officials including army chief General Raheel Sharif, ISI Director General (DG) Rizwan Akhtar, Corps Commander Karachi Lt Gen Naveed Mukhtar, Rangers DG Major General Bilal Akbar, Federal Defence Minister Khawaja Asif, federal interior secretary, federal chief secretary, Sindh Chief Minister Qaim Ali Shah, Sindh Governor Ishratul Ibad and MQM leader Farooq Sattar.
During the meeting it was decided that the ongoing operation against criminal elements in the city will be sped up, and will be extended to target not only criminal organisations but also their workers and abettors.
At least 43 people, including 17 women, were massacred near Safoora Goth when gunmen boarded the bus they were travelling in and shot them at a point-blank range. Six other women and two men were wounded in the brazen assault.
The gory incident sent ripples in the power corridors of Islamabad and Rawalpindi from where the prime minister and the army chief rushed to Karachi, sat together with representatives of the intelligence and law enforcement agencies and decided to accelerate the ‘targeted operation’.
Two of the wounded persons died from the bullet wounds, said on Thursday an official of the Sachal police station within whose jurisdiction the carnage was carried out. The two deaths took the toll to 45.