Updated

Two men found with several pipe bombs in their car near a Navy base were charged Monday with possession of an explosive device, authorities said.

A joint state-federal investigation was under way to see whether there was any terrorism connection but no link had been found yet, said FBI spokeswoman Denise Taiste. The Navy base is the site of a brig where enemy combatants have been held.

Ahmed Abda Sherf Mohamed, 24, and Yousef Samir Megahed, 21, both students at the University of South Florida in Tampa, were driving through the area on Saturday to vacation at a North Carolina beach for Mohamed's birthday, their defense attorney said.

"They admitted to having what they said were fireworks. Based on the officer's judgment at hand, based on what he had seen, we judged it to be other than fireworks," Berkeley County Sheriff Wayne DeWitt said.

Mohamed, 24, said he made pipe bombs from items he bought at Wal-Mart, according to an affidavit with his arrest warrant.

Defense attorney, Dennis Rhoad, said the men have a reason for having the devices and it would become clear in later court hearings.

"The defendants deny the allegations the state and the sheriff have made against them," Rhoad said.

Prosecutor Scarlett Wilson asked for high bond, which was set at $500,000 for Mohamed and $300,000 for Megahed, because she said the men were dangerous and a risk to flee.

Mohamed is a native of Kuwait and Megahed is Egyptian, the sheriff said. Both are in the country legally.

Ahmed Bedier, the executive director of a civil rights organization for Muslims in Tampa, criticized the arrest as racial profiling, an accusation South Carolina police refuted.

It's not clear if the item found in the vehicle is actually a bomb, said Bedier, of the Council on American-Islamic Relations.

"If it's clearly a pipe bomb that's a different story. Then there is cause for concern," Bedier said. "However, we have not seen consistent evidence that it is a pipe bomb. There is a lot of contradiction out there."

Megahed lives with his family and they voluntarily allowed the FBI to search their home in Tampa Monday, Bedier said.

"They're so confident that they don't have anything in their home that they gave the keys to some agents. The father voluntarily allowed them to go search the home unsupervised," Bedier said.

Mohamed and Megahed were stopped for speeding Saturday night on U.S. Highway 176 near Goose Creek, which is the site of the Naval Weapons Station and houses the U.S. Naval Consolidated Brig, a military prison where enemy combatants have been held.

They were heading west, away from Goose Creek, when they were pulled over about seven miles from the sprawling Navy facility, police said.

Officers became suspicious because the men quickly put away a laptop computer and couldn't immediately say what they were doing in the area or where they were going, DeWitt said.

A deputy then found what he thought were explosives in the 2000 Toyota Camry and called the bomb squad. Technicians confirmed the devices were pipe bombs and destroyed them, according to sworn statements in the arrest warrants.

Authorities closed a mile-long stretch of the highway Saturday night and didn't reopen it until about 4 a.m. Sunday.

University spokesman Ken Gullette said Mohamed is a civil engineering graduate student who came to the school in January. He earned his undergraduate degree in Cairo and was in the country on a student visa.

Megahed, who has permanent resident status in the United States, is an undergraduate and has been at the university since 2004, but has not declared a major, Gullette said.

Neither has ever been arrested by campus police or disciplined by the university, Gullette said. Both were enrolled in classes this summer. Gullette said the university is cooperating with authorities.

If convicted of the felony charge, the men would face from two to 15 years in prison.

Goose Creek, with a population of about 30,000, is about 20 miles north of Charleston.