its sad to hear it but i dont think this was done by da LTTE.
u c if they had done this they wudnt just trigger a samll hand grenade. they usually try to get sumthing big.
wat i think is dat sum guy who wanted to make a big seen in da zoo by putting out a bomb and they all da animals will get disturbed and then they will close da zoo for sumtime till da animals r calmed. it must hav been done by sum extremist group working for wildlife conservation.
after all y do u think da person blasted it in jst sum place than blasting it in a place where he finds a lot f ppl and also how come no one saw who blasted da bomb??