Immigration activist Jose Antonio Vargas was released from Border Patrol custody on Tuesday after being detained while trying to board a flight in Texas. 

In a statement released by the group Define American, Vargas did not offer further details on his release or brief detention.

Vargas, who is living in the country without a U.S. visa, was detained after traveling to the border town of McAllen, Texas. He said he wanted to visit with some of the children coming into the United States from Central American who have been detained while crossing the border.

Customs officials in McAllen, which is near the border, check identification of air travelers to determine if they are U.S. citizens or are authorized to travel in the United States. Pictures of Vargas in handcuffs appeared on social media on Tuesday morning after he attempted to board a plane out of McAllen-Miller International Airport.

A number of Democratic lawmakers and others on social media has called for his quick release after reports of his detention. He thanked supporters in a statement. 

"As an unaccompanied child migrant myself, I came to McAllen, Texas to shed a light on children who parts of America and many in the news media are actively turning their backs on," he said. "But what I saw was the generosity of the American people, documented and undocumented, in the Rio Grande Valley. 

"I've been released by Border Patrol. I want to thank everyone who stands by me and the undocumented immigrants of south Texas and across the country. Our daily lives are filled with fear in simple acts such as getting on an airplane to go home to our family. With Congress failing to act on immigration reform, and president Obama weighing his options on executive action, the critical question remains: how do we define American?"

Vargas, a high-profile activist, recently released his documentary film "Documented" on CNN. He is a former Pulitzer Prize winning journalist from The Washington Post

Vargas came to the country at the age of 12 in 1993 and has a passport from the Philippines. But he does not have a visa to be in the United States nor does he have any U.S. identification. He does not qualify for the Deferred Action Childhood Arrival program set up by the Obama administration in 2012 because he is too old.