Complex sentence: At this period the Bourj al-Barajneh camp was under siege by Amal militia,-Amal set up in 1974 by Musa Sadr-closest ally in Lebanon of the Syrian regime of Hafez al-Assad.
Split into simpler sentences: At this period the Bourj al-Barajneh camp was under siege by Amal militia. Amal had been set up in 1974 by Musa Sadr and was the closest ally in Lebanon of the Syrian regime of Hafez al-Assad.