SAN ANTONIO - Federal officials say eight Syrians have turned themselves over to immigration authorities along the Texas-Mexico border.

The Department of Homeland Security said Thursday that two families - two men, two women and four children - presented themselves Tuesday in Laredo and are being held by U.S. Immigration and Customs Enforcement.

It's not uncommon for Syrians and others from the Middle East to seek asylum in the U.S. through various routes.

However, the detention of the Syrians in Texas comes at a time of heightened national security concern from several governors who oppose a federal plan to accept 10,000 Syrian refugees in the wake of the Paris attacks.

In response to the detentions, Texas Gov. Greg Abbott tweeted, "THIS is why Texas is vigilant about Syrian refugees."