The fires disrupted classes _ leading to evacuations and early closures of at least three schools, officials said.
And fire officials worried about the potential danger both to first responders and to the public as engine companies raced to one emergency call after another.
``Calls have been too numerous to count and its been a real problem for us,'' fire spokesman James Gardner said at midday Wednesday. ``We've received at least 10 calls _ at some schools more than once.''
Classes were disrupted for the second straight day at Highlandtown Middle School in Hamilton after a trash fire was discovered on the second floor. Tuesday, police sprayed some students with either mace or pepper spray, after a melee erupted after the building was evacuated.
Officials closed two schools located in the old Northern high school building _ the Reginald Lewis High School and the W.E.B. Dubois High School at about 2 p.m. Wednesday after a fire was set on the third floor of the building.
Bonnie S. Copeland, the city schools chief, said school officials were sending in additional security officers on Thursday to troubled schools, including the Thurgood Marshall Complex, Highlandtown Middle School and W.E.B DuBois High School.
School officials were trying to recruit parents and community leaders to volunteer to help monitor the troubled schools.
Copeland said school officials also were exploring ways to make for lost school time, such as holding class after school or on Saturday.
Gardner said firefighters also responded to small fires at Forest Park and Northwestern high schools.
In each case, fire fighters found small fires set in trash cans, lockers or toilets that were quickly extinguished, Gardner said.
Officials established a continuous presence at Walbrook, Forest Park, and Thurgood Marshall high schools after a rash of malicious burning earlier this school year.
