An Ethiopian Airlines passenger plane was forced to abandon its landing in eastern Dire Dawa city after hitting into what appeared to be a swarm of locusts, an airline spokesman has confirmed to the BBC.

The spokesman did not give further details of Thursday's incident, but aviation industry websites are reporting that the Boeing 737-700 was forced to divert to the capital, Addis Ababa.

One website reported earlier that the insects were grasshoppers. It has posted a photo of the plane's nose cone smeared with dead insects

East Africa has been hit by its worst locust invasion for 25 years, which has devastated crops across the region.

Swarms can vary from less than one square km (0.38 square miles) to several hundred square km, and there can be at least 40 million and sometimes double the number in each square km of swarm, according to the UN's Food and Agriculture Organization (FAO).

The plane flew through a small swarm, before encountering a bigger swarm which reduced visibility, reports say.

The pilots tried in vain to clean the windscreen with the plane's wipers and after failing to land in Dire Dawa diverted the plane to Addis Ababa, about 30 minutes away.

The plane was on what is normally an hour-long journey from Djibouti to Dire Dawa. (BBC)