TAIPEI -?Taiwan's security chief says it received a warning of possible terrorist attacks in?Beijing as the mainland hold its annual parliamentary session.

The security bureau head Tsai De-sheng told?local legislative committee Monday that his bureau passed on a warning of planned attacks against the Beijing airport and the city's subway system to the mainland authorities following its receipt on March 4.

Tsai said the receipt of the warning prompted stepped up security measures at?airports in Taiwan, particularly on Beijing-bound flights.

He said it had no connection to a Malaysia Airlines flight bound for Beijing that has been missing since early Saturday.