Blancolirio does a good job of covering the interim report:
Two key points:
The Baikal Teal is not a very big bird, but a flock of them can contain hundreds of individuals. More of a swarm than a flock?
It is suspected the pilots initiated a go around before they hit the birds. If they had hit the birds the standard procedure would have been to continue the landing.
Based on this it seems a likely chain of events was that the pilots saw the flock, initiated a go around to avoid it but still hit the birds. Unfortunately this meant they were no longer in a landing configuration and now had no engines and very little time to fix matters.
These users thanked the author Vogoff for the post (total 4):
Patrick AL • Jasondn78 • Kobus Luttig • NunoCarreira