Macedonia charged a former interior minister and six officers of its security forces with murder on Friday in a 2002 ambush of what it said were innocent migrants set up to look like "Mujahideen terrorists".
The official MIA news agency said a parliamentary committee voted 6-to-2 to lift the immunity of former interior minister Ljube Boskovski. "They have approved the state prosecutor's request for his detention," it said.
"It was a monstrous fabrication to get the attention of the international community," Interior Ministry Spokeswoman Mirjana Kontevska told a news conference.
"Only a sick mind can construct and give the order for such a gross liquidation of seven people whose destiny ended like in a horror movie," she said.
According to police sources, the prosecution said a police chief was told to find migrants who could fit the description of terrorists.
She said the seven dead men - six Pakistanis and an Indian - were in fact economic migrants passing through Macedonia. They had been pin-pointed, kidnapped and killed in what Boskovski and his men claimed was a coup against global terrorism.
Bodies were filmed with handguns stuck in their waistbands.
"Nobody has the right on the basis of his own craziness to take someone's life in the name of the state," Kontevska said, in an apparent reference to Boskovski, who earned a reputation in office as an extreme nationalist.
Police sources said two of four officers in custody were ex-generals in the police force and a further two men had been charged but not yet arrested.
Boskovski told reporters: "Before I'm taken into custody, I solemnly declare I'm telling you the truth. I have not given any such orders to eliminate such a group."
"There was no order to kill civilians," he said. His rightist VMRO-DPMNE party lost a presidential election on Wednesday to Social Democrat Branko Crvenkovski, whose party has held power for 18 months.