Air France-KLM says it faces an uncertain medium-term outlook after recent terror attacks in Europe impacted on sales in the second quarter.

The Franco-Dutch airline group reported a 5.2% drop in revenues to €6.2bn (£5.2bn; $6.8bn) in the three months to June period.

The Paris-based firm said it is being affected by a high level of geopolitical uncertainty while there is "special concern about France as a destination", after a string of terrorist incidents in the country.

However, operating profit came in at €317m compared to €179m in the same period a year ago, mainly due to lower fuel costs.

Fluctuations in the exchange rate had a €104m negative impact on revenues in the second quarter.

Air France serves nearly 40 destinations in France and over 160 destinations overseas.

"The global context in 2016 remains highly uncertain regarding the geopolitical and economic environment in which we operate, fuel prices and the continuation of the overcapacity in the airline industry resulting in an increasing pressure on unit revenues and a special concern about France as a destination," the airline said in a statement.

Earlier this month, Germany's largest carrier Lufthansa slashed its profit forecast for the year amid a sharp drop in long-haul bookings to Europe.

The airline blamed "repeated terrorist attacks in Europe" and greater political and economic uncertainty in the region for the fall in demand.