"It's really business as usual," said Jeff Ratcliffe, head of the Irish Red Cross in Agadez, which had one of its vehicles stolen at gunpoint last month. "We will continue to work in the areas south of Agadez, but will not go north or east because there is a problem with bandits."
Michael Flachaire, head of mission for Action Against Hunger (AAH) in Niger, said: "We take events like this very seriously, considering that we lost 17 international staff in Sri Lanka last year. We will analyse the security situation this week, but for now, AAH will remain. When the time comes that we feel as though are personnel are in danger, we will pull out of northern Niger."
A UN staff member in Niamey confirmed that UN agencies working in the region have not left the region, although stricter security measures and curfews have been enforced.
Witnesses in Agadez said 20 armed men in jeeps and on motorcycles briefly fought with soldiers outside the airport in Agadez at around 7.30pm on Sunday evening.
The Nigerien Movement for Justice (MNJ), a rebel group that in interviews with IRIN has accused the central government in Niamey of neglecting the northern region and failing to develop the country, claimed responsibility for Sunday's attack at the airport.
The MNJ, which is led by remnants of a rebellion led by ethnic Touaregs in the 1990s, claims to have led four assaults on the Nigerien military since it launched its campaign in February. It is also accused of laying mines in the region of Iferouane, to the north of Agadez.
The government denies that there is a rebellion in the north and blames the recent attacks on bandits and criminals smuggling drugs and arms through the vast desert region.
The governor of Agadez Abba Malam Boukar banned travel between towns in northern Niger last week in response to what the government is calling increased banditry in the region. He also imposed a curfew in Agadez to be enforced by the army.