Suspected militants threw a grenade at Pakistan's paramilitary Ranger forces in Karachi in early April, killing four.
It was just another attack in what has become Pakistan's most violent city.
Roughly 20 million people live here.
There are almost daily reports of people killed by hired guns or militants such as the Taliban and Sunni extremists Lashkar-e-Jhangvi.
Imran Shaukat, the Police Senior Superintendent of East Karachi, says it is a complex situation.
"The targeted killing in Karachi is being done by various groups for various reasons," he explained.
"There is gang warfare, groups involved in it,
there are tentacles of terrorist organizations involved in it, and there is criminal elements involved in it as well.
According to the Human Rights Commission of Pakistan, more than 2,200 people died in ethnic, sectarian, and politically linked violence last year.
In early March, a large bomb blast in a Shi'ite neighborhood killed 45 people.
Militant Sunni Muslims, who consider Shi'ites to be heretics , were believed to be behind the attack.
Imtiaz Raza, a Shi'ite who works in a small street stall , says his family lives in fear.
"I am afraid to leave the house.
When I leave my area, I am afraid a hit man is following me," he confided.
"I'm afraid to go to the market.
Something already happened to my family.
My father-in-law and two brothers ran shops in the heart of a Sunni area for the last 32, 34 years,
and they were killed in broad daylight.
Police say they are trying to stop the killings.
Imtiaz Gul, head of the Islamabad-based Center for Research and Security Studies, agrees with police officer Shaukat that the violence in Karachi is multi-dimensional.
"The other dimension, of course,
relates to the increasing presence and activism by religio-political parties, who also play host to a number of militant groups including the Tehreek-e-Taliban Pakistan, Lashkar-e-Jhangvi and many others," he noted.
"Because Karachi is a huge commercial and financial center,
it also serves as an ATM for a number of militant groups who are out there challenging the writ of the state.
People were too afraid to speak to us on camera about Taliban violence.
Police since last August have arrested 191 target killers from different organizations, terrorist outfits as well as petty criminals.
But none have been convicted.
"There is a lengthy procedure that we have to follow.
We don't have any witness protection program.
Witnesses don't come forward, so we have to find some forensic evidence that connects them with the crime scene.
We are working on it, and hopefully we will get them convicted pretty soon.
But shopkeeper Raza says, while the wealthy of Karachi have armed guards and ride in armored vehicles, little is done—even by the police—to protect poor families like his.
active, determined, and often willing to use force
eg. We have militant bonds of friendship.
involving a lot of different but related parts
eg. It was a complex problem.
a person who is guilty of heresy
eg. He was regarded as heretic by the common people.
a large table or a small shop with an open front from which goods are sold in a public place
eg. The excited horse flung about in the stall.
a legal document from a law court that tells someone that they will be involved in a legal process and explains to them what they must do
eg. The police showed him the writ of search before entering the house.