The sanction was handed down by a government commission set up to combat violence in sport, which also warned soccer clubs that such incidents would not be tolerated and they should do all in their power to prevent them.
Celta were leading 1-0 at the Madrigal with about three minutes left when the canister landed near the visitors' goal and began spewing out a thick cloud of white smoke.
Spanish police have still not been able to find the culprit.
The players, some of whom were clearly suffering the effects of the gas, retreated inside the stadium and fans quickly left the ground, with many covering their mouths and noses and in obvious distress.
The match was eventually restarted after about half an hour in an almost empty arena and Celta forward Nolito made it 2-0 in the 90th minute. ($1 = 0.7293 euros)
- Sports & Recreation