A Nevada school district and a teacher's union are set to appear in court Wednesday after the district asked a judge for a temporary restraining order to put an end to an alleged sickout that caused a spike in staff absences.

The hearing comes as the district and the union are locked in a contract dispute.

The Clark County School District, which includes Las Vegas, claims that through a "targeted and coordinated rolling-sickout strike" the Clark County Education Association's licensed educators "forced the closure of three Clark County schools and severely disrupted the operations of two others" between Sept. 1 and Sept. 8, according to court documents shared by the Nevada Independent.

The Clark County Education Association represents more than 18,000 educators in the Clark County School District, the nation's fifth-largest.

Nevada law prohibits strikes by public sector employees. The district claimed that the absentee level at the affected schools is "unprecedented."

The district claimed that the mass absences affected one school per day throughout most of the week, before causing two school closures on Sept. 8. Four more schools closed on Tuesday, followed by another Wednesday, according to Las Vegas ABC affiliate KTNV.

"It defies logic to suggest that these mass absences constitute anything but the type of concerted pretextual absences that [Nevada law] plainly defines as a strike," the district said in court documents.

The district is asking the court to intervene and stop the alleged strike, claiming the situation will only continue, according to court documents.

"This strike is the culmination of Defendants’ months-long campaign to pressure the District into more favorable bargaining terms by credibly threatening that there would be no school without a contract," the district said in court documents.

The union has been rallying over contract demands and to ensure students have a licensed teacher in every classroom, according to posts on social media.

The union said it had no knowledge of absences from last week and denied that they were in any way associated with the union's actions in a statement to the Nevada Independent.

The union did not immediately respond to ABC News' request for comment.