Linear A script has been found on seals, instruments, and tablets on the islands of Crete, Phera and Melos and as yet has not been deciphered. The script may have evolved from an older linear hieroglyphic system, and seems to comprise a syllabary, a set of ligatures and a set of ideograms. It uses between 70 and 100 symbols and although it shares many symbols with Linear B, using the syllables associated with Linear B in Linear A writings produces words that are unrelated to any to any other surviving language in Europe or Western Asia.

For more information on the problems facing decipherment of Linear A I have written an article here: Linear A: The Problems of Decipherment

Examples of Linear A can be seen here:
Cretan Writing
Prehistoric Documents from Crete
Linear A