By Khaled Yacoub Oweis and Angus MacSwan AMMAN, Feb 22 (Reuters) - Syrian President Bashar al-Assad's forces rained rockets and bombs down on opposition-held neighbourhoods of the city of Homs on Wednesday, reducing buildings to rubble and killing more than 80 people, including two Western journalists. The barrages marked an intensification of a nearly three-week offensive to crush resistance in Homs, one of the focal points of a nationwide uprising against Assad's 11-year rule and its ferocity has caused international outrage.