BETHLEHEM, Pennsylvania (AP):

For the second time in three days, a rally for the Republican presidential ticket invoked Democrat Barack Obama's middle name, Hussein, in an attempt to add to doubts about his background, faith and campaign.

Before John McCain and running mate Sarah Palin arrived at their rally in eastern Pennsylvania, Lehigh County Republican chairman Bill Platt twice used Obama's middle name. Neither McCain nor Palin referred to Platt's remarks when they spoke, but their campaign quickly issued a statement saying it did not condone "this inappropriate rhetoric."

McCain has called the use of Obama's middle name both improper and inappropriate and once apologised after a supporter warming up a rally used it. Referring to Hussein - a name Obama shares most famously with deposed Iraqi dictator Saddam Hussein - is widely viewed as an effort to link Obama to radical Islam even though he is a Christian with no such ties.

Shouts of 'socialist,' 'terrorist' and 'liar' from supporters followed McCain's references to Obama at Lehigh University.

In Florida on Monday, a sheriff told voters at a Palin rally: "On November 4, let's leave Barack Hussein Obama wondering what happened."