A distributed denial of service (DDoS) attack has taken down another bitcoin exchange.

European bitcoin and altcoin exchange BTC-e went offline on Thursday morning after receiving a DDoS stream of requests around 5:30 a.m. Eastern Standard Time. The exchange confirmed the attacks on Twitter: “DDoS attack on our server #btce”

BTC-e’s operations resumed several hours after the attacks.

This isn’t the first time the Bulgaria-based bitcoin exchange has been taken down by a DDoS attack. In January, BTC-e was also knocked offline for several hours before it was able to return to full service.