An attorney for nine activists detained in Arizona for nearly a week after attempting to cross the border from Mexico into the U.S. said American authorities have yet to respond to their requests for release.

Lawyer Margo Cowan said she is asking the U.S. to allow the detainees to remain here on what's known as humanitarian parole, essentially to permit admission to the country because "their presence in America will serve an important public interest."

Three of the activists left the U.S. for Mexico expressly to participate in the protest on Monday. All were apparently raised in the United States after their parents came here illegally.

Still, Cowan said, due to their long-standing ties to the U.S. and lack of any cultural connection to Mexico, they should be allowed entry.