Union City police are continuing to investigate an incident last week in which contaminated brownies sickened five Logan High School students, but no other arrests are imminent in the case, a police lieutenant said Thursday.

The students reported becoming ill or feeling like they were under the influence on Jan. 20 and 22. Two of the students experienced convulsions and had to be hospitalized, New Haven Unified School District officials said.

Medical test results for the two hospitalized students revealed the presence of marijuana, but no other illegal drugs.

"The main thrust of this case was obviously to make sure there's no heroin, so that's been done and we're happy with that," police Lt. Ben Horner said.

This week, police arrested an 18-year-old Union City man for possession of marijuana and a 17-year-old Conley-Carabello High School student who was found on the Conley-Carabello campus in possession of six marijuana brownies, a pipe, and 13 bags of marijuana.

Horner said the 18-year-old man is not believed to have been involved in passing out the brownies that hospitalized the students. He was on probation and was arrested after being found at the same location as the 17-year-old suspect.

He has since been cited and released.

The 17-year-old suspect was taken to juvenile hall and will not be charged as an adult, Horner said.

On Friday, the school district sent phone messages to parents advising them about the incident and asking them to remind their children to be cautious about accepting food from others.

Anyone with information about the case is asked to call the Police Department at (510) 471-1365 or the anonymous tip line at (510) 675-5207.