Tunis said Friday that the kidnappers of a Tunisian diplomat in Tripoli and an embassy colleague are demanding the release of Libyans jailed in Tunisia on terrorism charges.

Al-Aroussi Kontassi, the diplomat, was abducted Thursday in the Libyan capital, a month after Tunisian embassy employee Mohamed ben Sheikh was seized in Tripoli.

A Tunisian diplomat was kidnapped Thursday in Tripoli in unknown circumstances, a Libyan security source told Agence France Presse, just two days after armed men seized Jordan's ambassador.

A Tunisian source confirmed the abduction and identified the diplomat as Al-Aroussi Kontassi, without giving further details.

A female Libyan security guard at the U.S. embassy in Tripoli, who disappeared after leaving work on Monday night, was "likely" kidnapped, the mission's spokesman said.

While it was not immediately known if there was any connection with the woman's work, the news came after gunmen abducted Jordan's ambassador as he traveled to work in Tripoli Tuesday morning, shooting at his car and wounding his driver.

Masked gunmen kidnapped Jordan's ambassador to Libya as he rode to work in Tripoli on Tuesday, shooting at his car and wounding his driver, officials said.

It was the latest targeting of Libyan leaders and foreign diplomats in the increasingly lawless North African country, three years after NATO-backed rebels ousted autocratic leader Moammar Gadhafi.

The United States on Monday denounced as "unconscionable" threats made against the Libyan prime minister and cabinet members, saying the country needed to move forward.

"At a time when Libya most needs political consensus to move forward its democratic transition, extortion by physical attack must not hijack the process of peaceful dialogue," State Department spokeswoman Jen Psaki said in a statement.

The Libyan trial of more than 30 top figures from Moammar Gadhafi's deposed regime opened Monday, but proceedings were adjourned as key defendants, including onetime heir apparent Seif al-Islam, were absent.

The adjournment until April 27 came just 40 minutes after the trial started, as rights groups voiced doubts that the defendants, accused of abuses during the 2011 uprising that toppled the regime, would get a fair trial.

Fugitive jihadist commander Mokhtar Belmokhtar is hiding in Libya, from where he plans to mastermind terrorist attacks across Africa's Sahel region, security sources told Agence France Presse on Sunday.

The elusive Islamist, who staged a deadly siege of an Algerian gas plant in January last year, was said to have been killed in northern Mali two months later, although security experts have since expressed doubts over the reports.

Libya's prime minister Abdullah al-Thani stepped down on Sunday, saying he and his family had been the victims of a "traitorous" armed attack the previous day.

Thani quit less than a week after parliament tasked him with forming a new cabinet and a month after it ousted his predecessor for failing to rein in the lawlessness gripping the North African country.

Libya's oil exports are likely to quadruple from current levels and hit 1 million barrels per day by mid-June after rebels ended a blockade of two terminals, OPEC Secretary General Abdullah El-Badri said Friday.

"I think the first one million barrels will come in two months' time, but after a million it will take some time. Because the main challenge now is the security," El-Badri said at an international oil conference in Paris.

Libya's National Oil Co (NOC) on Thursday lifted a force majeure on a crude export terminal recovered from rebel hands, opening the way for renewed exports.

The army announced Wednesday it had taken control of al-Hariga and Zueitina ports under a deal to end a crippling nine-month blockade by rebels seeking autonomy in the country's east.