Pakistani police say a suspected militant has killed a lawyer from the country's minority Ahmadi sect over blasphemy allegations.

Local police officer Nazim Ali says security forces have arrested the attacker following the killing in eastern Punjab province on Thursday.

The slain lawyer, Saleem Latif, is from a prominent Ahmadi family and was a cousin of Pakistan's 1979 Nobel physics laureate Abdus Salam.

A spokesman for the Lashkar-e-Jhangvi militant group later claimed responsibility for the attack. Ali Bin Sufyan says Latif was killed for adhering to the beliefs of the Ahmadi sect.

The Ahmadi faith was established in the Indian subcontinent in the 19th century by Mirza Ghulam Ahmad, who followers believe was a prophet.

Pakistan's declared Ahmadis non-Muslims in 1974 and they are often targeted by Sunni militant groups.