The Croats, beaten by France in the 2018 final in Moscow, had the better of the chances, with Dejan Lovren having an effort cleared off the line and Nikola Vlasic's close shot saved by the legs of Morocco goalkeeper Yassine Bounou.
Morocco striker Youssef En-Nesryi might have given the north Africans an early lead but was unable to get a decent touch onto Hakim Ziyech's dangerous cross. In the second half Achraf Hakimi's powerful free-kick was parried by Croatia goalkeeper Dominik Livakovic.
Belgium and Canada meet at in Wednesday's other Group F match at Al Rayyan (9pm SA time).
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