Another threat against West Islip High School investigated, officials say

For the second time this week authorities are investigating a "threat of violence" made against West Islip High School, school district officials said.

Suffolk County police officers, including a canine unit, conducted a search at the school on Thursday after the latest threat was posted on what district officials described only as "a social media website." That threat, reported in a 911 call at 2:34 p.m., initially led to the high school building being placed on lockdown status, the district said in a message to students and family on the school district website.

Officials said the search Thursday found no evidence of a threat and said that, "due to a vague reference to the middle schools," police searched those buildings as well -- but found no evidence of threat there.

Police confirmed the building searches and said the district was being "extra vigilant" on Friday. Police said there are extra patrols in the area Friday .

"The safety of our students and security of our schools is of utmost concern," the district said in the online statement, adding: "The West Islip School District and Suffolk County Police are taking this incident very seriously." It said additional information regarding the threat was being withheld at this time, "so as not to compromise the investigation."

On Monday, police said West Islip High School was the target of a threat of a bombing and a shooting that was found to not be credible. A threat made Monday against another Suffolk high school, Mount Sinai, resulted in the arrest of a 15-year-old student there.