KANDAHAR, Afghanistan - The Taliban on Monday threatened to kill four Afghan medical personnel and their driver unless the government releases two Taliban commanders, seeking a deal similar to the prisoner swap that won an Italian journalist's freedom last month.

The threat came a day after the hard-line militia beheaded Ajmal Naqshbandi, an Afghan translator seized March 5 along with journalist Daniele Mastrogiacomo of the Rome-based La Republicca newspaper, after authorities refused another prisoner exchange.

Afghan President Hamid Karzai condemned the killing as the work of "enemies of Afghanistan," while Afghan journalists staged a protest in the capital.

A spate of abductions has highlighted the lawlessness of southern Afghanistan, where the Taliban remains strong despite the presence of thousands of foreign troops. The kidnappings have also prompted a debate over the ethics of negotiating with kidnappers.

In the latest kidnappings, the Taliban said it seized a doctor, three nurses and their driver on March 27 in Kandahar province.

"If the government does not release our two Taliban commanders, then we will give the same punishment as we did with Ajmal (Naqshbandi)," Shahabuddin Atal, who claims to speak for senior Taliban commander Mullah Dadullah, told The Associated Press on Monday.

The Taliban had made a similar demand in exchange for the release of Naqshbandi, a freelance journalist and translator who was seized in southern Helmand province. Atal said Naqshbandi was beheaded in Helmand's Garmsir district and that his family could find his body there.

Mastrogiacomo was freed March 19 in a swap for five imprisoned Taliban militants. The deal has been criticized by Afghan lawmakers and foreigners working in Afghanistan as an incentive for militants to stage more kidnappings.

"In exchange for the Italian journalist, the Afghan government and foreigners together handed over five Taliban. He was a foreign journalist," Atal said by telephone from an undisclosed location.

"When we asked for an exchange of two Taliban commanders for the Afghan journalist, the Afghan government did not respond, and they didn't try to negotiate for Ajmal's release," he said.

This proves that "this government is working only for foreigners, not for Afghans," Atal said.

Karzai last week defended the prisoner swap that secured Mastrogiacomo's release by saying the incident had threatened Italian premier Romano Prodi's government. He ruled out further exchanges.

On Monday, a statement from his office said the Taliban were supposed to release both Mastrogiacomo and Naqshbandi in exchange for the five militants, but reneged on the deal. It said the government had continued to push for the translator's release, but received no specific demands from the kidnappers.

The Taliban has also claimed it kidnapped two French aid workers and three Afghan staff members. The five went missing last week in southwestern Nimroz province.

Separately, the founder of an Italian aid organization pressed for the release of an Afghan staff member believed to have been taken into Afghan custody after Mastrogiacomo's release.

On Sunday, Sayed Ansari, a spokesman for Afghanistan's intelligence service, accused Rahmatullah Hanefi of helping the Taliban kidnap Mastrogiacomo, Naqshbandi and a driver who was also beheaded.

But Gino Strada, founder of the aid group Emergency, told Italian Sky Tg24 television in an interview on Sunday that Prodi's government knows that Hanefi was trustworthy because he had been given $2 million to deliver to the Taliban to free an Italian photographer who was kidnapped in Afghanistan last year.

Strada's claims of a ransom paid for Torsello, and the beheading of Naqshbandi despite the prisoner-swap deal, prompted several opposition lawmakers in Italy to demand that Prodi's government brief parliament on the matter. Some even called for a commission of inquiry and the resignation of the foreign minister.

In a statement, Prodi denounced partisan bickering. "No one ... should doubt the correctness of the government's actions in this, as in all delicate international events," the statement said.