By Syed Raza Hassan
KARACHI, Pakistan (Reuters) - Pakistan's army chief on Wednesday ordered an inquiry into the death of a political activist in custody of the paramilitary Rangers force, the first known inquiry since 2013 when Rangers launched a major crime crackdown in the city of Karachi.
The Muttahida Qaumi Movement (MQM), a secular party that has long dominated the port city of Karachi, has accused the Rangers of having carried out dozens of extra-judicial killings of party members since 2013, something the Rangers deny.
Aftab Husain, a prominent activist and aide to Farooq Sattar, the MQM leader in the National Assembly, was arrested at his house on Sunday and died on Tuesday.
The Rangers initially said Husain died of a heart attack, but the MQM said Husain was "extra-judicially killed" in the force's custody.
"COAS has directed to hold an inquiry to find out truth in the case of Aftab Ahmed," the army said in a statement, referring to the army chief, General Raheel Sharif, who is chief of army staff (COAS).
The MQM has held sway over Pakistan's commercial hub for years and law enforcement agencies, its opponents and many residents have accused it of racketeering, abduction, torture and murder of opponents in its bid to maintain power.
The party denies links to crime.
The Rangers' campaign against crime in the city has been widely seen as part of a broader effort by the army to exert its influence over civilian politics.
In a separate statement, the head of the Rangers said the force had set up a "high level investigating committee" to look into Husain's death and had suspended the officials suspected of involvement.
Prime Minister Nawaz Sharif in August formed a "grievances redressal committee" to address MQM concerns, but the body has not published findings. The army is not known to have launched any inquiries into deaths of MQM members since 2013.
Last year, the U.N. Working Group on Enforced or Involuntary Disappearances referred 55 cases of what it called illegal abductions of MQM workers to the government, concluding a "pattern of specific targeting" of the MQM by Rangers.
While Karachi murder rates have dropped sharply and many businesses welcome the Rangers' operation, the force has been dogged by allegations of brutality.
Army chief Sharif said recently "across the board accountability" was essential, linking anti-corruption efforts to the war on Islamist militants.
General Asim Bajwa, the army spokesman, said in a Tuesday media interview six senior army officials had been "punished" over corruption charges unrelated to the Rangers inquiry.
(Writing by Mehreen Zahra-Malik; Editing by Drazen Jorgic, Robert Birsel)