Georgian loyalists and rebel forces (after a week of fighting) P (agreed to) Q (a cease fire today) R (in which 51 people were killed) S The correct sequence should be

Since, the sentence starts talking about the forces, the continuing statement would be the statement talking about the consensus of the forces on a particular point i.e. Q follows. R will be the next statement as it connects Q by stating that they agreed for a cease fire. The next statement would be talking about the reason of the cease fire, therefore, P follows and S would be the concluding statement which makes a coherent paragraph. The correct formation would be, ‘Georgian loyalists and rebel forces agreed to a ceasefire today after a week of fighting in which 51 people were killed’.