Dear Muslim,
Since iam living in Saudia, i have sent copies of my documents as per CIC request, the only originals i have submitted are IELTS and the Police Clearance Certificate from Yemen.
In Yemen, From what i know that there is no designated notary public or a commissioner of oaths to serve the public, but in your case if you have any documents that are in Arabic, you will need first to Translate them from Authorized Translator then attest them from Ministry of Foriegn Affairs in Yemen.
If you want to make Affidavits (inside Yemen ) you will need to do the same as well, beside that i think you will need a lawyer to attest them as well.
Regards,