Image copyright AP Image caption Students Kayla Martinez (right) and Brianna Hawk sued their school district for banning controversial bracelets, citing freedom of speech

The US Supreme Court has rejected an appeal which sought to ban students in Pennsylvania from wearing controversial breast cancer awareness bracelets.

The Easton Area School District had prevented youths from wearing bracelets emblazoned with "I (heart) Boobies!", alleging the words were lewd.

Two students legally challenged the ban in 2010, citing freedom of speech.

The US court's decision leaves in place an earlier ruling by a federal appeals court overturning the ban.

'Vulgarity'

"I am happy we won this case, because it's important that students have the right to stand up for a cause and try to make a difference. We just wanted to raise awareness about breast cancer," student Brianna Hawk said in an American Civil Liberties Union of Pennsylvania statement following the Supreme Court decision.

Image copyright AP Image caption The "I (heart) Boobies!" bracelets are sold by the Keep A Breast Foundation to raise breast cancer awareness

Brianna, along with Kayla Martinez, sued the school district after it banned seventh- and eighth-grade students from wearing the bracelets prior to national breast cancer awareness day in October 2010.

The students refused to remove the bracelets - sold by the breast cancer awareness group Keep A Breast Foundation - and were reportedly given one-and-a-half day suspensions.

In April 2011, a district court issued an injunction preventing the school from disciplining students as a result of wearing the bracelets.

The Easton Area School District said it was "disappointed" following the Supreme Court decision on Monday.

The decision "robs educators and school boards of the ability to strike a reasonable balance between a student's right to creative expression and school's obligation to maintain an environment focused on education and free from sexual entendre and vulgarity", according to a statement released by the school district to US media.