(Sharecast News) - Low-cost African airline Fastjet saw revenues soar last year, driven by an increase in passenger numbers in Zimbabwe and Mozambique.Passenger numbers shot up 45% in Zimbabwe and by 575% in Mozambique, which only operated for two months in 2017, resulting in an overall increase in yields of 33%.However, Fastjet saw losses widen 267% to $41.2m, principally due to one-off exceptional items arising from the group's capital raise in December, which triggered impairments of $23.9m against balances held in its balance sheet, the company said in a statement.Looking forward, Fastjet told investors that its recent Tanzanian divestitures and a significantly stronger balance sheet had laid the foundations for an improved overall performance through 2019.Chief executive Nico Bezuidenhout said: "In 2018, we took significant and decisive action to right-size the group and ensure the business has a solid platform on which to build future growth."Whilst these cost-cutting measures were at times painful, our newly-sized operations provide Fastjet with a materially enhanced strategic position to pursue the growth opportunities on offer on the continent."As of 0850 BST, Fastjet shares were flying 1.75% higher at 1.45p.