ISLAMABAD: Senior journalist Saleem Shahzad was laid to rest in the Qayyumabad graveyard of Karachi on Wednesday.
Earlier his funeral prayers were offered at Mubarak Mosque in which hundreds of people including family members and friends participated.
Hundreds of mourners turned out for the burial of Shahzad, who was tortured and said he was threatened by the country's intelligence services, as his colleagues demanded protection.
Saleem Shahzad, a 40-year-old father of three, vanished after leaving home in Islamabad to appear on a television talk show, two days after writing an article about links between rogue elements of the navy and al Qaeda.
His grief-stricken relatives have demanded a full investigation but have not apportioned blame for his killing, which came five years after he was briefly kidnapped by the Taliban in Afghanistan and accused of being a spy.
Shahzad carved out a career writing about the plethora of militant networks operating in Pakistan, and warned human rights campaigners before his disappearance that he had been threatened by the Inter-Services Intelligence.
US Secretary of State Hillary Clinton condemned his murder and said his "reporting on terrorism and intelligence issues in Pakistan brought to light the troubles extremism poses to Pakistan's stability".
Shahzad's body was found Tuesday, about 150 kilometres (93 miles) southeast of Islamabad.
Police said it bore marks of torture."The cause of death is torture and there are several signs of torture on his body and face," said Ashok Kumar, one of the doctors who carried out a post-mortem at Islamabad's Pakistan Institute of Medical Science.
Another doctor told AFP that Shahzad's lungs and liver had been damaged, and that the body was swollen and bore more than 15 signs of having been beaten.
Around 300 people, mostly relatives and journalists, attended the funeral prayers and Shahzad was buried in a local cemetery in the well-off Seaview neighbourhood in his home town of Karachi.
"We have lost everything. What can we do now?" sobbed his son, Fahad Saleem, resting on the shoulder of an uncle.
The Pakistan Federal Union of Journalists announced two days of mourning and a spokesman said members would organise protests nationwide on Friday.
"I can't blame anyone at the moment. I'll analyse the whole episode before making any statement," Wasim Fawad, a brother of Shahzad, told AFP.
"My brother was killed for writing the truth. He paid a huge price, he sacrificed his life but always spoke the truth."
Interior Minister Rehman Malik confirmed that a police investigation had been ordered and promised a reward of nearly $30,000.
But reporters and press groups say previous enquiries into the killings of journalists have not been made public and said they expected little this time.Reporters Without Borders says that 16 journalists have now been killed since the start of 2010 in Pakistan, which it ranks 151st out of 178 countries in its press freedom index.
Malik says allegations of ISI involvement to be probed
Interior Minister Rehman Malik has given his assurance to probe allegations of Inter-Services Intelligence (ISI) involvement in the abduction of journalist Saleem Shehzad.
Malik was speaking to the media after visiting the residence of Shehzad.
Ali Dayan Hasan, Human Rights Watch (HRW) representative in Pakistan, has been quoted in Asia Times Online as saying that he suspected that Shehzad had been picked up by the intelligence agency.
Hasan says Shehzad had sent him an email in October 18, a day after he claimed to have met ISI personnel at their headquarters who had asked him about a source for a separate story. The email says he had refused to disclose his source despite threats from the personnel.
Shehzad had asked Hasan to release the email in case of his death as he feared something would happen to him.
Shahzad, 40, who worked for an Italian news agency and an online news site registered in Hong Kong, went missing on Sunday. His body was found on Tuesday.
He disappeared two days after writing in an investigative report in Asia Times Online that al Qaeda carried out last week's attack on a naval air base to avenge the arrest of naval officials suspected of having links to the group.
US condemns killing
US Secretary of State Hillary Clinton on Tuesday condemned the abduction and murder of Shahzad.
"The United States strongly condemns the abduction and killing of reporter Syed Saleem Shahzad," she said in a statement.
"His work reporting on terrorism and intelligence issues in Pakistan brought to light the troubles extremism poses to Pakistan's stability," she said.
Clinton said Washington welcomed Pakistan's launch of a probe into the killing.