COSCO’s computer networks in the Americas remained completely severed from the Internet on Thursday, almost 48 hours after the Chinese shipping giant reported it was hit by a ransomware attack.

In a statement published Thursday, COSCO officials said the failures affected networks in the US, Canada, Panama, Argentina, Brazil, Peru, Chile, and Uruguay. The statement said people who wanted to reach COSCO employees in those countries should use special email addresses, many of which were hosted by Yahoo and Gmail. Attempts to reach COSCO’s US-based website were unsuccessful. COSCO officials said main business operation systems were performing stably and that ports in California and the UK remained open.

The statement—and posts on COSCO’s official Twitter and Facebook accounts—didn’t disclose the reason for the outage. The Press-Telegram of Long Beach, California, however, reported on Tuesday that the China state-owned shipping company was infected by ransomware. The report didn’t identify the name or strain of the ransomware, which generally encrypts computer hard drives and demands a payment by digital currency to decrypt it.

In one tweet, a COSCO representative said company officials initially isolated all its regional networks after experiencing a “breakdown” and gradually reconnected most of them after confirming they were secure. The tweet didn't say why the networks in the Americas remained offline.

In June 2017, the NotPetya ransomware outbreak that shut down computer networks worldwide had a particularly severe effect on A.P. Moller-Maersk, the world’s largest container ship and supply vessel company. In an earnings statement two months later, Maersk estimated that the infections cost it as much as $300 million in lost revenue.

It’s too early to tell how the damage sustained by COSCO will compare. Based on statements that COSCO’s main operations remain unaffected and that networks outside of the Americas are working normally, there’s reason to think the outbreak was contained before it could spread. A full assessment may not be possible for weeks.