On The Ground newsletter: Get a weekly dispatch from our international correspondents Get a weekly dispatch from our international correspondents Get a weekly international news dispatch Email * SIGN UP I would like to be emailed about offers, events and updates from The Independent. Read our Privacy noticeGunfire and loud explosions echoed around Niger’s international airport in what two security sources described as a "terrorist attack", before calm returned to the Niamey capital on Thursday morning. Two security sources described the incident, which occurred shortly before midnight, as a "terrorist attack" and said security had been reinforced around the airport following an internal alert about an imminent attack on the site. They said a store of uranium currently held at the airport had not been affected by the attack. The heavy gunfire began shortly before midnight on Wednesday and continued for over an hour, the Reuters witness said.