Suicide bombers have launched simultaneous attacks on military and mining targets in Niger, prompting renewed fears that attacks by al-Qaida-linked jihadists could spill across borders in West Africa's Sahara desert.

Cars packed with explosives were detonated at the same time almost 100 miles apart, killing at least 17 soldiers at a military barracks in Agadez, and injuring dozens at a plant owned by French nuclear firm Areva in Arlit.

Niger's defence minister said the attacks were carried out by terrorist groups believed to have links with neighbouring Mali and Libya. "We suspect armed groups linked to al-Qaida, maybe operating in Mali but who have come through southern Libya," said Mahamadou Karidjo. "The situation is under control and the search for the other attackers is under way."

The Movement for Unity and Jihad in West Africa (MUJAO) – one of the groups that triggered a war in Mali after seizing control of the country's north – has claimed responsibility for the attack.

"Thanks to Allah, we carried out two operations against the enemies of Islam in Niger," MUJAO spokesman Abu Walid Saharoui told AFP. "We attacked France, and Niger because of its co-operation with France in the war against the Sahara."

The attacks are the latest to heighten concerns about the effects of the war on Mali on neighbouring countries in the sparsely populated Sahara region, which has seen a burgeoning growth in jihadist activity supported by kidnappings and the trade in drugs and other smuggled goods over its porous desert borders.

In January Algeria was drawn deeper into the crisis in Mali when a group led by former al-Qaida in the Islamic Maghreb (AQIM) leader Mokhtar Belmokhtar crossed from Mali into Algeria and took more than 800 people hostage at an oil plant at In Aménas, killing 39.

Claims that Thursday's attack involved militants travelling from southern Libya come after the Guardian reported last month that southern Libya is becoming an important route for militants being pushed out of Mali and taking advantage of instability since the fall of Col Gaddafi to plan further attacks.

Witnesses say the attacks happened as residents of Agadez and Arlit prepared for morning prayers around 5am. A security expert in Niger's capital Niamey told the Guardian that one of the attackers was still armed with explosives and is holding a soldier hostage.

"We are hearing that four of the five of the attackers were killed by their own explosives, but that the last is continuing the attack and is holding a soldier hostage," said Moussa Akfar.

Areva, the world's second largest uranium producer, said that its mine was "badly damaged" forcing it to stop production.

Although Areva has been attacked by AQIM in the past – with five French workers taken hostage at the site in 2010 – the latest attacks are the first of their kind in Niger. Niger has been singled out as a target for its role in the military intervention in Mali, for its relationship with France – which obtains 20% of its uranium from Niger – and with the US, which

signed an agreement this year to establish a new military base in the country.

This week Nigeria, which borders Niger to the south, asked Niger for help fighting its militant Islamist group Boko Haram, members of whom are reported to be operating in southern Niger. Last month Niger's military participated in a raid against Boko Haram fighters in the Nigerian town of Baga, near the border with Chad.

"These attacks are an inevitable consequence of the decisions our government has taken," said Akfar. "But our intervention in Mali was not a mistake – we share borders with Mali, and if we had not intervened, the crisis there would have affected us anyway.

"We are a poor country, but now we are going to have to find the means of heightening our security, or else face further attacks."