Armed gunmen have kidnapped 10 staff members at the Tunisian consulate in Libya's capital, Tripoli, the Tunisian Foreign Ministry has said.

The ministry statement called Friday's attack "a vile aggression" against Tunisian sovereignty and a flagrant violation of international laws and diplomatic norms".

The statement said Tunisia's government was monitoring the situation and working to secure the release of its employees.

"All government services are following developments with interest in coordination with Libyan, regional and international parties, to liberate without delay the Tunisian mission team and guarantee its safety," the ministry statement read.

Mokhtar Chaouachi, a spokesman for the Tunisian foreign ministry, said it was not clear whether the attackers were holding the hostages on site or had taken them elsewhere. He also said he did not know whether the attackers had opened fire or had made any demands in exchange for the captives.

Khalifa Ghwell, who holds the post of prime minister for the Islamist-led, militias-backed government in Tripoli, said that authorities were working to win the release of the employees, the Associated Press reported.

He declined to comment on the circumstances of their abduction, saying: "Everything will be fine, God willing."

Al Jazeera's Nazanine Moshiri, reporting from Tunis, said Tunisian officials were holding a crisis meeting but were being reticent about who was behind the kidnapping.

"Some people are saying that all of this connected to a man named Walid Kalib, a member of Libya Dawn, which took control of Tripoli and forced the government to move to Tobruk in the east," Moshiri said.

"Walid Kalib was arrested here in Tunisia in May, he's facing charges of kidnapping.

"In May, more than 250 ordinary Tunisian were detained but then released."

Tunisia is one of the few countries which still has a mission in Tripoli, which is controlled by a government not recognised by the UN.

Anti-ISIL protests

Meanwhile, seven people were shot dead in the eastern city of Derna while marching against the Islamic State of Iraq and the Levant (ISIL) group.

The protesters were marching against the group's main base in Derna after Friday prayers when gunmen shot at the crowd, killing several people, and wounding about 30.

The demonstrators were angered at the number of foreigners coming to join the armed group, residents told the Reuters news agency.

Nine suspected ISIL members were killed during separate clashes on Friday with other armed groups in Derna, a source in one of those movements said.

A warplane taking off from a base in the eastern city of Benghazi held by the official government later attacked Derna port, a military spokesman said. The attack came after ISIL had tried to ship out its wounded in boats, a resident said.

The fighting in Derna, a long-time gathering point for hardliners, first erupted on Tuesday after a leader in the Majlis al-Shura group was killed.

Majlis al-Shura, which enjoys local support going back to the revolution, responded by declaring holy war against ISIL.

ISIL has seized territory in the eastern Libyan cities of Derna and Sirte as the country's security situation descends into chaos.

The armed group is at war with both the Tripoli-based, and Tobruk-based governments of Libya.

Source: Al Jazeera and agencies