KENT, Wash. -- The Kent School District has started a lawsuit against the Teachers Union, seeking an injunction ordering teachers to return to class while negotiations continue.

District Superintendent Dr. Edward Lee Vargas said at a news conference Tuesday that the teachers' strike was illegal.

UNCUT: Raucous News Conference With Kent Superintendent
UNCUT: Kent Teachers Cheer, Jeer At District News Conference

"We don't want to see any disruption of our services for any reason," said Vargas.

During the announcement, some in the crowd heckled Vargas, shouting out objections as the he explained the reason for the legal action.

Other audience members cheered and clapped loudly.

Vargas said he was concerned about the other district employees, such as cafeteria workers and bus drivers, who are not able to work.

On Wednesday, a group of parents said they are planning to make their own signs and join teachers on the picket lines outside schools.

Other parents said they find it hard to side with the teachers.

"I think they should be going back to school. I understand that there's a lot of problems going on with the schools, such as class sizes, but I think they need to go back to school so we don't have to jeopardize the kids' learning," said parent Macrina Andreas.

The district's move has shocked and angered teachers.

The 1,700 teachers have been on strike since last Thursday as officials continue to negotiate a new contract.

The 25,000 students in the district have remained in limbo as the start of classes continues to be delayed. The school year was scheduled to start Monday.

Teachers said the last contract offer from the district fell short on key issues such as wages and class size.

A hearing concerning the injunction will be held on Wednesday.

Injunctions have been granted 30 times in the state. In most instances, teachers have ignored the order and continued to strike.

In 2003 in Marysville, an injunction ended a 50-day strike.