At least six persons were killed and four injured when unidentified gunmen attacked a Christian welfare organization in Pakistan's southern port city of Karachi, police said.
The gunmen broke into the office of the Institute for Peace and Justice (IPJ) located at the third floor of Rimpa Plaza located in the heart of the city and opened indiscriminate firing with automatic weapons.
Six people including three Christian and three Muslims died on the spot while four others sustained injuries.
According to police, it appeared two gunmen took part in the assault and managed to fled the scene after the gory incident. They tied their victims to chairs, then shot them in the head.
The police have cordoned off the 13-storey building and the adjoining area.
Police officer Tariq Jamil said the gunmen attacked the officeat 10:30 local time, adding no foreigner has either been killed orinjured.
He said after entering the office, the killers took everyone at gun point and put a tape on their mouths. All the victims were shot in the head with pistols.
He was of the view that there was no similarity in this incident with those of Murree, Taxila and Islamabad. He said in those cases, the attacks were targeted but in this case it did not seem to be targeted because Muslims were also working in this office.
Two Bishops of the Christian community, Sadiq Daniel and Simmon Prierra, also reached the spot. However, they refused to comment on the incident and left the site after remaining there for over half an hour.
The IPJ has been operating for the past 30 years, working to obtain basic employment rights for municipal and textile workers and running programs with local human rights groups. It has never taken part in religious politics in Pakistan.
So far, there is no clue about the culprit behind the terrorist attack but police officials believe a string of attacks on Christian and western targets have been carried out by militants opposed to the US presence in neighboring Afghanistan.
Last week, Karachi police arrested 27 activists of an extremist Islamic group, the Harkat-ul- Mujahideen Al Almi, which was allegedly involved in the suicide car bombing on the US Consulate and the attack on a bus that killed 11 French nationals in May.
Attacks on Christians and westerners in recent months have resulted in the death of at least 30 people and the injury of about 100.