Pakistani security agencies on Thursday arrested two suspects involved in the car bomb blast outside the house of the 2008 Mumbai terror attack mastermind and chief of the banned Jamat-ud-Dawah (JuD) Hafiz Saeed, an official said.
The Crime Investigation Department (CTD) has arrested two suspects, one of them a Christian, who had a connection with the sale and purchase of the car used for the blast, a CTD official told PTI.
The official did not disclose the identity of the suspects.
However, the Associated Press named one of the arrested as David Peter.
Intelligence agencies have arrested a man from the Lahore airport on the suspicion of his involvement in the blast, Geo News reported.
Quoting police sources, the report said the man was asked to get off a Karachi-bound flight a few minutes before departure.
He was taken to an undisclosed location for further investigation, the report said.
"We are getting a lead from the arrested persons to the main culprits," the CTD official said, adding that different teams have been formed to probe the matter.
The arrests came after the security agencies conducted raids across different cities of Punjab in connection with the blast.
A first information report (FIR) has been registered against 'unknown terrorists' under terrorism and other charges, said police.
Three persons were killed and 21 others injured when the powerful car bomb exploded outside Saeed's residence at the Board of Revenue (BOR) Housing Society in Johar Town on Wednesday morning, resulting in serious injuries to some police officers guarding his house.
The windows and walls of Saeed's house were damaged from the impact of the blast.
No group has claimed responsibility for the blast.
The CTD official told PTI that it was a remote-controlled device installed in a car parked at the police picket near Saeed's house.
"Some 15 kilograms of explosives were planted in the car that was stolen from Gujranwala. Through the CCTV it was seen that the car driver reached the police picket and parked it there and left 15 minutes before the blast," the official said.
Although Saeed's residence remained safe with some windows and glass damaged, a number of other houses and shops falling within 100 square feet radius of the blast site were damaged.
Two houses and four shops were completely damaged.
Punjab Chief Minister Usman Buzdar has promised to compensate those affected by the blast.
Meanwhile, police and Rangers personnel have been deployed outside and in the vicinity of Saeed's residence. Security has also been put on high alert in Lahore.
Earlier on Thursday, Interior Minister Sheikh Rashid Ahmed said that Punjab police are close to arresting the culprits responsible for the blast outside Saeed's residence.
'Officials have achieved great success during the investigation process. Punjab police will soon arrest the suspects and give good news to the people,' Rashid tweeted.
Inspector General Police Punjab Inam Ghani had said that hostile intelligence agencies could be involved in this blast.
The CTD and intelligence agencies have collected the evidence from the crime scene, the sources said, adding that ball bearings, pieces of iron and the vehicle's parts have been preserved.
Investigative agencies have also started geo-fencing the area to help with the blast probe, Geo TV reported.
In geo-fencing, a virtual geographic boundary around an area is created by means of Global Positioning System (GPS) or Radio Frequency Identification (RFID) technology, enabling software to trigger a response when a mobile device enters or leaves the area.
The 71-year-old radical cleric has been serving a jail sentence at the high-security Kot Lakhpat Jail in Lahore for his conviction in terror financing cases.
The blast sparked rumours that Saeed was present in the house.
Meanwhile, condemning the terrorist incident, Pakistan Peoples Party (PPP) Chairman Bilawal Bhutto Zardari has warned that Pakistan could see an increase in such attacks due to the 'flawed Afghan policy' of the current government led by Prime Minister Imran Khan.
Addressing the media at the Parliament House in Islamabad on Wednesday, Bilawal said such incidents could increase as Pakistan's policy in Afghan peace process 'is not correct' and added that some terrorist organisations are also active across the border, the Express Tribune newspaper reported.
"I had demanded on the floor of the (National) Assembly that whatever this government is doing covertly and through the backdoor should be brought before the representatives of the people.
"The government should tell us what its policy is," he said, referring to Pakistan's role in brokering the peace deal between Afghan Taliban and the United States.
Saeed, a United Nations designated terrorist whom the US has placed a $10 million bounty on, has been convicted for 36 years imprisonment in five terror financing cases. His punishment is running concurrently.
Saeed-led JuD is the front organisation for the Lashkar-e-Tayiba (LeT) which is responsible for carrying out the 2008 Mumbai attack that killed 166 people, including six Americans.
The US Department of the Treasury has designated Saeed as a Specially Designated Global Terrorist.
He was listed under the UN Security Council Resolution 1267 in December 2008.
The global terror financing watchdog Financial Action Task Force (FATF) is instrumental in pushing Pakistan to take measures against terrorists roaming freely in Pakistan and using its territory to carry out attacks in India.