REUTERS reports that hand granade was placed into stove:
"A Kosovo police spokesman said the grenade exploded in a stove used to heat the classroom shortly after lessons began at around 7.50 a.m. (0650 GMT) at the Trajko Peric school in the village of Veliko Ropotovo near the eastern town of Kamenica.
"The stove was completely destroyed and some parts of the classroom as well," said spokesman Veton Elshani."
http://today.reuters.com/news/articlenews.aspx?type=topNews&storyID=2006-11-21T134723Z_01_L21791378_RTRUKOC_0_US-KOSOVO-SCHOOL-GRENADE.xml&WTmodLoc=NewsHome-C1-topNews-9
What a viscious plan. Stoves in Serb enclaves are using coal for fuel. it is so easy to put hand granade under the coal allready put into stove, and just wait for teacher or janitor to set fire in stove. And while children are gathering arround stove to get warm. BOOOM! Instant Independant Kosovo! Free of Christians!
My guess is that they were warned.....to avoid injuries, bringing more attention, but leaving a clear message. Also, in the link you provided, notice....
"Some 10,000 ethnic Albanians died and 800,000 fled during Serbia's 1998-99 war against separatist guerrillas."
They are still sticking to the BS about 10,000 Albanians killed....in this article.