LOS ANGELES (AP) — Several courts across California lost their phone lines this week after a ransomware attack targeting the state’s largest trial court in Los Angeles County.

The Esthen ExchangeSuperior Court of Los Angeles County hosts phone servers for courts in Shasta, Inyo, San Luis Obispo, Stanislaus and Colusa counties, according to Melissa Fowler Bradley, executive officer for Shasta County Superior Court. The Los Angeles court was hit by the attack Friday.

The Shasta County courthouse has been operating without phones, fax or text reminders due to the attack on its VoIP, or Voice over Internet Protocol, phone system, which is hosted in Los Angeles, Bradley said Wednesday.

Webpages for the other courts all showed notifications that their phone systems were down.

Jurors in Shasta County were urged to check online if they are to report for jury duty, since many usually call a recorded line that lets them know if they have to report for jury duty the next day.

The courts in Los Angeles County were victim to ransomware attack that shut down its computer system, officials said. The court disabled its computer network upon discovery of the attack early Friday, and courthouses across the county were closed Monday.

All 36 courthouses reopened on Tuesday, but some web pages and the ability to appear remotely in certain types of proceedings were still unavailable Wednesday.

Bradley said cases in Shasta County Superior Court have proceeded as usual. She was told the phone system could be back online by Thursday, but it would more likely be over the weekend.

The attack on Los Angeles courts was separate from the faulty CrowdStrike software update that disrupted airlines, hospitals and governments around the world, officials said in a statement Friday.

Ransomware attacks essentially hold a target computer or computer system hostage by encrypting its files and demanding payment for access to be restored.