The number of public schools in Suffolk without full state accreditation has tripled, the Virginia Department of Education announced Friday.

Booker T. Washington, Elephant’s Fork and Mack Benn Jr. elementary schools, plus King’s Fork Middle School, now join King’s Fork and Lakeland high schools as accredited with warning.

Suffolk Public Schools had expected the outcome, Superintendent Deran Whitney said in an email.

“We knew the number of schools missing accreditation this year would increase, considering the new assessments and the increase in rigor,” he said.

“While having six of the 69 schools in South Hampton Roads that are accredited with warning in Suffolk, we are pleased the remaining 13 remain fully accredited.”

The outcome follows a statewide trend, with the proportion of Virginia schools that are fully accredited dropping from 93 percent for 2012-2013 to 77 percent this year.

In line with Whitney’s reaction, state education officials have blamed increased rigor in reading, writing and science Standards of Learning tests last instructional year, as well as the continued effects of more challenging math assessments introduced in 2011-2012.

The superintendent maintained that schools without full accreditation should not be thought of as “bad.”

Meanwhile, Michael Debranski, chairman of the School Board, said he was surprised more schools didn’t miss benchmarks for full accreditation.

“I’m concerned that we are not making the cut,” he said. “We need to make sure we get our kids up on this,” since the focus has turned increasingly to SOL scores in recent years.

Improvement plans required by the state for the six schools, which are in addition to those the district demands of all public schools in Suffolk, will include “specific strategies and practices to assist in areas where pass rates are below the achievement levels required for full accreditation,” Whitney said.

“The primary thing teachers are encouraged to do to narrow performance gaps is to differentiate instruction and to provide interventions to students when deficits are noted.”

Administrators and school leaders do this by examining subgroup data for patterns using “student performance by questions,” and “reporting categories of the state assessments to address what may appear to have been a deficit previously.”

Different math and reading assessments for this year will be administered three times to help teachers target instruction. “For the most part, less testing will take place allowing for more teaching,” Whitney said.

Six public schools in Virginia — though none in Suffolk — are now under the authority of the state’s new Opportunity Education Institution for being denied state accreditation. A further 19 schools across the state have now been accredited with warning for three consecutive years, meaning that the institution’s governing board could vote to take them over, as well.

Whitney opined the legislation that created the institution and its powers is unconstitutional. “Supervision of schools in each school division is the responsibility of the school board,” he said.

In a column published on today’s Opinion Page, Gov. Bob McDonnell disagreed, quoting from Section 9 of the Virginia Constitution: “The General Assembly may provide for the establishment, maintenance, and operation of any educational institutions which are desirable for the intellectual, cultural and occupational development of the people of this Commonwealth.”