A threat against President Obama's niece, a player on Princeton's women's basketball team, prompted increased security at the Tigers' NCAA Tournament game at Maryland, said a person familiar with the situation says.

The person spoke to The Associated Press on condition of anonymity on Monday night because no details had been released about the threat.

Princeton was facing Maryland in the second round of the tournament Monday night at the Terrapins' arena. On Saturday, President Obama attended Princeton's 80-70 victory over Wisconsin-Green Bay in the first round.

Princeton freshman forward Leslie Robinson is Obama's niece. Her father, Craig Robinson, is the brother of first lady Michelle Obama.

A phone message threatening Leslie Robinson was left at Maryland and the threat was taken seriously, according to the person who spoke to the AP.

The threat was first reported by USA Today.

Neither the president nor the first lady attended Monday's game, although Supreme Court Justices Sonia Sotomayor and Elena Kagan sat near Princeton's bench.