Pakistan's President Pervez Musharraf has stepped into a controversial rape case, saying he believes an accused army captain is not guilty.
Eight people died in the tribal attack on the Sui gas plant
The rape of a doctor at a gas plant in Balochistan province sparked violence that left eight people dead.
Gen Musharraf said accusations against the officer were baseless but vowed to bring to justice those involved. He said they should be hanged.
The case sparked outrage among Baloch nationalists and women's groups.
Gen Musharraf on Thursday called the rape of the doctor, who was working in a hospital at a natural gas plant in the Sui region of Balochistan, a heinous act.
He said whether those responsible were men in uniform or civilians they would not be spared.
However, he said the captain was certainly not involved.
He said more evidence had been collected during investigations and once the judicial probe was complete, the findings would be made public.
Three petroleum officials have been arrested for allegedly concealing and destroying evidence but the alleged rapist or rapists remain at large.
Initial reports said the doctor had been subject to gang rape. But in an interview with Britain's Guardian newspaper she refers only to one rapist. On Wednesday she told the AFP news agency that one other person may have been at the scene.
Last Friday it was revealed that DNA samples taken from the scene did not match those of the suspects.
The victim was being asked to identify the alleged rapists from video and audio recordings of 13 suspects.
The doctor told the Guardian newspaper that she was "very scared".
"In Pakistan there is no law, no protection, nothing. Who can we trust? Nobody," she said.
Rights campaigners have also spoken out for the doctor.
"In this country a woman has no status," Shershah Syed, of the Pakistan Medical Association, told the Guardian. "She is an object, like a cow or a bucket."
Militants of the Balochistan Liberation Army said they carried out an attack on the Pakistan Petroleum gas plant on 11 January to avenge the alleged rape eight days earlier.
The militants fired hundreds of rockets and mortars at a guards' outpost and a gas purification installation.
The plant and three pipelines were damaged. Gas supplies were severely disrupted and not reconnected for a week.
The attack prompted the authorities to send thousands of paramilitary troops as guards.
The army has said it will clear homes from the area surrounding the gas plant as a security measure.
It also said it would set up a new garrison at Sui, angering Baloch nationalists.
The nationalists want more autonomy, a greater share of the wealth from the province's rich mineral reserves and more investment in development and employment.