NEW YORK (CNN) -- A U.S. citizen from Texas has been arrested and charged with making false statements to investigators probing the bombings of U.S. embassies in Kenya and Tanzania.

Wadih El Hage, of Arlington, is being held without bail in New York, and federal officials have indicated that he could face additional, more serious charges, perhaps as soon as Monday. He is the fourth person so far, and the only U.S. citizen, to face charges in connection with the August 7 blasts.

According to court papers, El Hage once served as the personal secretary for Osama bin Laden, a millionaire Islamic militant who U.S. officials believe masterminded the African attacks, which killed 258 people, including 12 Americans.

He lived in Kenya from 1994 until 1997, when he returned to the United States.

El Hage allegedly lied to the FBI when he told agents he did not know Mohamed Saddiq Odeh, who was brought to the United States last month to face murder charges related to the embassy bombings. He also allegedly gave false statements concerning his ties to bin Laden's chief military commander, who drowned in a 1996 ferry accident in Tanzania.

El Hage's tire store in Texas

El Hage managed Texas tire store

El Hage lived in an Arlington apartment with his wife, a U.S. citizen, and seven children. He managed a tire store and claimed to make $400 a week.

Co-workers say he left without warning Monday to fly to New York. Authorities say he was subpoenaed to appear before a grand jury investigating bin Laden and was subsequently arrested.

Sources tell CNN that records El Hage kept for bin Laden, which were seized in Kenya during the bombing investigation, may provide a financial road map to bin Laden's suspected terrorist empire.

The FBI also alleges that El Hage was a close associate of Haroun Fazil, a Comoros Islands native who on Thursday was charged with murder and conspiracy in connection with the African bombings.

Fazil remains at large, and the U.S. State Department has offered a $2 million reward for his capture.

In additional to Fazil, Odeh and El Hage, one other man faces charges in connection with the embassy bombings -- Mohamed al-'Owhali, who was charged with murder and conspiracy after he was captured and returned to the United States.

Uganda holds 18 in allegedly anti-U.S. plot

On Friday, a senior State Department official told CNN that 18 people are now under arrest in the African nation of Uganda for allegedly planning an attack against American interests. FBI agents have gone to Uganda to investigate.

And the government of Tanzania announced that it had expelled 14 non-Tanzanians who had been detained and questioned in connection with the bombing of the U.S. Embassy in Dar es Salaam.

The group included five Iraqis, five Sudanese, two Libyans, one Turk and one other person whose nationality wasn't specified. Immigration Department spokesman Herbert Chilambo said lack of direct evidence to connect them to the bomb attack was the major reason they were deported and not charged.

Correspondent Susan Candiotti contributed to this report.