Editor's Note: For updates on this developing story, see the IPT Blog.

**Updated December 9, 9:00 a.m. EST

A Pakistani newspaper reports the arrest of five foreign nationals after a raid in a town called Sargodha. The raid took place at the home of a member of the Jaish-e-Muhammad, a Pakistani movement designated as a terrorist group by the U.S. Treasury Department in 2001.

According to the report, "The DPO told that these people had been living in Sargodha since Nov 30 and it was quite a possibility that they were engaged in acts of terrorism." It names the five as Ahmed Abdullah, Waqar Hassan Khan, Eman Hassan, Yasir and Rami Zamzam and describes them as two Yemenis, an Egyptian, a Swede and a U.S.-born Pakistani.

December 8: Federal investigators are searching for a Howard University dental student and four other missing Muslim men reported missing from the Washington, D.C. area, the Investigative Project on Terrorism (IPT) has learned. There is concern they may have been sent abroad to train for jihad. The five were last seen November 29.

The identities of two of the missing men, Howard student Ramy Zamzam and Waqar Khan, have been mentioned in online postings, including a Facebook page that was set up Monday for friends to offer their support. Some of those pages, however, appear restricted to friends and associates.

It is not clear where the men are believed to have gone, but an informed source told the IPT that at least one left behind a farewell video.

According to the Facebook and Twitter postings, Zamzam is among the missing. He has been active in the Muslim Students Association, serving as president of the MSA DC Council. A Howard University spokeswoman has not responded to questions from the IPT.

The disappearance comes as U.S. officials are increasingly concerned about the threat of homegrown Islamist extremism. This concern is prompted by a spike in attacks like the Fort Hood massacre, and conspiracies broken up by law enforcement before any attacks took place.

President Obama noted the increase during his speech last week at West Point explaining the Afghanistan surge:

"In the last few months alone, we have apprehended extremists within our borders who were sent here from the border region of Afghanistan and Pakistan to commit new acts of terror."

Homeland Security Secretary Janet Napolitano echoed that sentiment in a speech last week. "We are seeing young Americans who are inspired by Al Qaeda and radical ideology," she said.

On Monday, federal prosecutors charged a Chicago man with six counts of conspiracy tied to the 2008 terrorist attacks in Mumbai, India that killed more than 170 people, including six Americans. That attack was believed to be carried out by Lashkar-e-Taiba, a Pakistani terrorist group that has been implicated in conspiracies in Virginia, Toronto and elsewhere.

On the surface, at least, the situation in Washington resembles the case of 20 young Somalis who disappeared from the Minneapolis area a year ago. They are believed to have made their way back to Somalia, where they trained with the Al-Shabaab terrorist group.

At least three of those men have died, including one who became the first known American citizen to carry out a suicide bombing. Fourteen people have been indicted in relation to the Somali recruitment effort.

Little is known about Zamzam. In 2008, he was part of a student effort in northern Virginia to solicit mosques throughout the country to raise money to build a new mosque. He also posted a comment indicating he thought women were required by Islam to cover themselves and that Muslim women who did not faced punishment from God.

"Those that don't, then woe to them for a day where all will be held accountable for what they put forth in the life of this world, and Allah SWT wrongs no one, and He is the Most Just, Most Merciful."