KARACHI: Sohail Ahmed was picked up last December by a bunch of burly men outside his local mosque in Karachi and shoved into an SUV. It was the last time his family saw him alive.

A month later his body was found on a football field, bearing marks of severe torture.

Ahmed's relatives and officials from the Muttahida Qaumi Movement (MQM), the political party to which he belonged, believe his death fits a pattern of extra-judicial killings carried out by security forces as part of a “clean-up“ operation aimed at driving down crime and militancy.

“They were agencies from our country. Is this not terrorism? To pick someone up, torture and kill them?” asked his sister Humaira Ifthikhar, tearfully.

Family members of Sohail Ahmed - AFP

Karachi, a sprawling port city of 18 million people, has been wracked by criminal, ethnic and political violence since the 1990s. In recent years, it has also become a home to Islamist militants. The MQM, the dominant political force in the city, stands accused by critics of running a violent mafia-like organisation, but the party strongly denies this and presents itself as a voice of political moderation and secularism.

Some of those who have lost their lives in encounters with security forces on Karachi's streets are believed to have been suspected of involvement in the party's alleged armed wing, or to have links with the Taliban or Al Qaeda. An operation by police and paramilitary forces launched in 2013 has brought murders down from a rate of seven or eight a day to two or three, along with a 23 per cent fall in street crime.

Read more: Extrajudicial acts by police aimed at curbing crime, says DIG

The campaign took a fresh turn two weeks ago when paramilitary Rangers raided the MQM headquarters, seizing weapons and arresting activists, including one accused of murdering a journalist. But critics say the crackdown has involved an unacceptable disregard for the judicial process, with security personnel effectively “executing” suspects in staged clashes known locally as “encounter killings”.

The police deny that such killings take place. Ghulam Haider Jamali, chief of the province's police force, instead extols what he calls effective police action.

“Karachi was having extraordinary challenges. Karachi has terrorist infested areas. They come from across the country, they were killing police personnel, they were targeting Shias and innocent citizens of the city, the Ulema (religious leaders), members of the civil society,” he said.