Hello people!
*Warning: Pure Speculation Ahead.*
Forces from the Mountains of Mirkwood came to the lands between the Eastern eaves of Mirkwood and the River Running, where there is little watch(after all, it looks to Esgaroth) They were small enough not to be noticed, but strong enough to drive away Gollum's guard and capture the Slinker. 100 would be the maximum estimate.
They were organized as a lightly armed hit-and-run force(you would have to be light if you had any hope of escaping from the elves on their own turf...and some did escape) How they crossed the Forest River? Probably by boats(unless there's a ford there I haven't heard of)
Yours, if you want to
->The True Son of Finrod, and of Amarië the Vanyar
[ October 20, 2003: Message edited by: Nilpaurion Felagund ]