Pakistani police say they plan to ask a court to charge five Americans arrested in early December with terrorism, and will seek life imprisonment sentences against them.

The young Muslim men, who are from the Washington, D.C., area, were captured in the eastern Pakistani city of Sargodha. The case spurred fears that Westerners are traveling to Pakistan to join militant groups.

SLIDESHOW: Homegrown Terror Threats

Tahir Gujar, a senior police investigator in Sargodha, said Thursday that the men would appear in an anti-terrorist court on Jan. 4. He said police had almost concluded their investigation and that they were "certain that these five Americans wanted to carry out attacks in Pakistan."

Gujar didn't say what authorities believe the men intended to target.