Malik Ishaq, who had been detained last week, was in a prison convoy in Punjab province when supporters opened fire in an attempt to free him, said police.
They said Ishaq was killed in a gun fight along with his two sons and 11 militants in Muzaffargarh district.
Lashkar-e-Jhangvi has been behind some of the most violent attacks on Shia Muslims in recent years.
Punjab Home Minister Shuja Khanzada confirmed the news to AFP news agency, while a doctor at Muzaffargarh District Hospital said 14 bodies had been received there.
Six police officers were also reported injured but correspondents say the details are unclear, and they have not been seen by the media.
Lashkar-e-Jhangvi was banned in Pakistan in 2001 and designated a terrorist group by the US in 2003.
The group is accused of killing hundreds of Shia Muslims in Pakistan.
The US House Ethics Committee has voted to release its report on former Republican Representative…
ABC News has agreed to pay $15 million to President-elect Donald Trump to settle a…
South Korea’s parliament has voted to impeach President Yoon Suk Yeol over his failed attempt…
Israeli war planes have carried out more than 100 air strikes in Syria on December…
President-elect Donald Trump has threatened to impose 100% tariffs on the BRICS countries if they…
Syrian troops have withdrawn from the city of Aleppo following an offensive by rebels opposed…