The Swiss-based operator of the Russian Nord Stream 2 gas pipeline said on Wednesday its mobile and fixed network lines were not reachable for the time being and it had shut down its website amid hacking attacks.

"We can confirm that we have taken down this website due to serious and continuous attacks from outside," the company said on the web site, which now consists of only one main page with the message.

Nord Stream 2 AG said Swisscom was not able to provide a proper mobile phone number transfer, "as promised and negotiated."

Earlier on Wednesday, the operator denied media reports that it had filed for insolvency.