The US Citizenship and Immigration Services (USCIS) on Tuesday revealed that an estimated 133,000 unique pieces of mail containing H-1B petitions. H-IB visas are often used by hundreds of foreigners, including Indians, to work or study in that country.

However, this is lower that the original USCIS estimate of 150,000 that the agency has based on amounts from manifests received along with the mail.

USCIS brought out the updated number following a physical count of the mail. Each piece of mail may contain more than one H-1B petition. "It will take USCIS a substantial amount of time to open and sort through that volume of mail," the agency said in an official release.

As of Wednesday, 28,052 of the cases sorted are H-1B petitions subject to the FY 2008 congressionally mandated cap. 4,703 cases are exempt from the FY 2008 H-1B cap as employers filed those petitions for aliens holding a master's degree or higher from a US institution.