Honda Motor Co., facing a U.S. safety probe, strengthened its recall of U.S. cars to replace potentially defective Takata Corp. air bags linked to several deaths.

Japan's third-biggest carmaker said late Thursday it was adding to its recall an undisclosed number of cars from model years 2001 to 2006 that were sold or registered in humid areas where the air bag inflators are thought to be most vulnerable to rupture.

Honda said that "it is not aware of any claimed injuries or fatalities that have been confirmed" related to the issue. More than 17 million cars built by 10 manufacturers have been recalled worldwide over Takata air bags, which can rupture and send metal shards into the passenger compartment.