No person shall depart from, or attempt to depart from India unless he holds in this behalf a valid passport or travel document.
     Explanation.--For the purposes of this section,--
         (a) "passport" includes a passport which having been issued by or under the authority of the Government of a foreign country satisfies the conditions prescribed under the Passport (Entry into India) Act, 1920 (34 of 1920), in respect of the class of passports to which it belongs;
         (b) "travel document" includes a travel document which having been issued by or under the authority of the Government of a foreign country satisfies the conditions prescribed.