Locals in Niger's historic city of Agadez are optimistic that its inclusion on UNESCO's list of World Heritage sites will bring tourists back after years of unrest in the area drove visitors away from its famed mudbrick buildings.

"The news has swept across the city like sand in the desert. It's incredible, thank you UNESCO!" Hadil, an Internet cafe manager in Agadez, told Agence France Presse over the telephone from Niger's capital Niamey.

Over a thousand people demonstrated in several towns and cities in France on Saturday in a show of support for four hostages who have been held by al-Qaida's north African branch for 1,000 days.

Thierry Dol, Daniel Larribe, Pierre Legrand and Marc Feret -- mostly working for French public nuclear giant Areva and its subcontractor Satom -- were kidnapped in Niger by militants belonging to al-Qaida in the Islamic Maghreb (AQIM) on September 16 in 2010.

Gunfire broke out at a paramilitary barracks in the Niger capital Niamey late Tuesday, residents said, with the source of the shooting unclear.

"The shooting began around 21:30 (20:30 GMT). It scared everyone," one local resident told Agence France Presse, in a comment confirmed by others.

Several "terrorists" were among 22 inmates who escaped a prison in the Niger capital Niamey during unrest in which three guards were killed, the government said Sunday.

They included Cheibane Ould Hama of Mali, who was convicted of killing four Saudis and a US citizen, Justice Minister Marou Amadou told a press briefing, adding that Hama was "actively sought".

An armed group attacked the main prison in the Niger capital Niamey on Saturday, killing at least two guards, Justice Minister Marou Amadou said, less than a week after twin suicide bombings claimed 20 lives in the west African country.

"The civilian prison of Niamey was attacked. We have confirmation of the death of two guards," Amadou told Agence France Presse, adding that the attack was carried out by "an armed group that we have yet been unable to identify".

France wants to work with Libya against militant groups on its territory but will not take military action in the country without U.N. backing, President Francois Hollande said on Friday.

Asked about media reports of France preparing an intervention against Islamist groups in southern Libya, Hollande told interviewers from broadcasters France 24, RFI and TV5Monde there were no plans in the works.

The Islamists who carried out two attacks last week in Niger which killed 38 people did not come from Libya, as charged by the Niger authorities, Libyan Prime Minister Ali Zeidan said Monday.

Such allegations "are without basis," Zeidan said after meeting EU President Herman Van Rompuy in Brussels.

Niger's president said Monday that attackers who bombed an army base and French-run uranium mine, leaving 38 people dead, entered his country from southern Libya, where he warned further attacks were being planned on Chad.

"For Niger in particular, the main threat has moved from the Malian border to the Libyan border. I confirm in effect that the enemy who attacked us... comes from the (Libyan) south, where another attack is being prepared against Chad," said President Mahamadou Issoufou.

The attackers who staged deadly twin bombings at an army base and French-run uranium mine in northern Niger came from neighboring Libya, Niger's President Mahamadou Issoufou said Saturday.

Pointing to the porous nature of the borders in the region, he warned that other "infiltrations" were possible and that Niger needed to examine what other security measures it needed to better defend its territory.

The jihadist group led by Algerian Mokhtar Belmokhtar that claimed twin suicide car bombings in Niger that killed at least 20 people threatened on Friday to launch further attacks in the country.

"We will launch further operations" in Niger, the group said in a statement posted on Islamist Internet forums that also threatened France and countries involved militarily in battling Islamist extremists in Mali.