21.   Saudi and U.S. officials also disagree on possible clues.

22.   Some are looking to the slightly earlier-than-usual announcement as a possible clue to the recipient.

23.   The only possible clue to his identity was a pair of orange shorts he was wearing, which had washing instructions printed on them in German.

24.   The newspaper said police were reading a novel by Uruguayan author Carlos Reherman to find possible clues to the crime.

25.   Fire investigators were raking through the wreckage of the building on Sunday looking for possible clues to the cause of the fire.

26.   But the reason for the hijacking remained unclear, as attention turned to possible clues in the passenger list, which has not been released in full.

27.   The reason for the hijacking remained a mystery, as attention turned to possible clues in the passenger manifest, which has not been released in full.

28.   Pilet has also ordered investigators to dig under the Cheiry farmhouse for possible additional clues.

29.   Police sealed off the blast site while forensic experts sifted through the wreckage for possible clues.

30.   The fax was at first considered a possible clue to the identies of the attackers.