Martin Luther King, Jr. Courthouse, Newark.

Federal court facilities in Newark were closed for deep cleaning Thursday after several employees in the Martin Luther King Jr. and Frank Lautenberg courthouses tested positive for the COVID-19 virus.

The two Newark courthouses will remain closed through April 6, according to the order signed Wednesday night by Chief Judge Freda Wolfson of the District of New Jersey.

Judges in Newark will continue to work remotely, and electronic filing continues uninterrupted during the closure, Wolfson said. Federal courthouses in Trenton and Camden are not affected by the closure.

The closure comes after recent moves by New Jersey's federal courts to continue all criminal and civil trials scheduled to begin before April 30. No new grand juries are being empaneled through that date, although sitting grand juries are authorized to continue meeting.

Judges have been encouraged to conduct proceedings by telephone or videoconferencing, and to take measures to avoid out-of-town travel of any litigant, witness or attorney. Hearings, conferences, sentencings, change-of-plea hearings, and bench trials are being conducted as each judge sees fit.

Anyone diagnosed with coronavirus or who has had contact with such people are also banned from entering federal courthouses.

The Newark courts are not alone in facing closure due to the COVID-19 virus. In Philadelphia, the James A. Byrne Courthouse, home to the U.S. Court of Appeals for the Third Circuit and the U.S. District Court for the Eastern District of Pennsylvania, was closed at noon on Wednesday and will remain closed through Sunday. The building was closed because two lawyers who appeared for court later showed symptoms of COVID-19.

In addition, federal courts in San Jose, California, Detroit and Harrisburg, Pennsylvania, have been closed in the past 48 hours after visitors or employees tested positive for COVID-19.