WARSAW, March 30, 2008 (AFP) - Border checks at airports in nine Schengen area newcomers, mostly from the ex-communist bloc, vanished at midnight Sunday, allowing 400 million people passport-free travel in the 24-country zone.

Malta and eight fellow 2004 European Union entrants -- ex-communist Poland, the Czech Republic, Estonia, Latvia, Lithuania, Hungary, Slovakia and Slovenia -- all dropped passport checks for air passengers who are Schengen state citizens.

The move puts the final touch to the expansion of the Schengen zone which first saw the end of border checks at land and maritime frontiers in newcomer states last December 20.

Most have seized the opportunity created by Schengen entry to upgrade airports that have benefited from a boom in passenger traffic since EU entry.