As aftereffects of last week's tragedies continue touching the community, few people outside the fences of the Edgefield Federal Correctional Institution know about a more subtle connection between the Augusta area and terrorist attacks.

Until Thursday, neither Edgefield Police Chief Lanny Ross Jr., nor Edgefield Mayor John Pettigrew, nor Edgefield County Sheriff Adell Dobey had been told the prison holds a convicted co-conspirator in the 1993 plot to topple the twin towers, carried out by radicals loosely tied to Osama bin Laden.

The U.S. Bureau of Prisons confirmed Ahmad Mohammad Ajaj, 35, has been in the small town in South Carolina since February. Mr. Ajaj, one of the men said to have hatched the 1993 bombing plan, was convicted in 1994 for his role and is serving a sentence of 114 years and 10 months.

His charges include explosive destruction of property, conspiracy to damage a building with an explosive device, interstate transport of explosives and use of a forged passport.

''I think it's something we should be aware of,'' Chief Ross said.

Inmate Ahmad Mohammad Ajaj is being held in Edgefield's federal prison. SPECIAL

Although the prisons bureau would not answer specific questions about Mr. Ajaj, Edgefield facility spokesman Mike Smith said all federal prisons have been on heightened alert since the mass killings in Washington, New York and Pennsylvania.

''It has nothing to do with who we're housing,'' he said.

Mr. Ajaj is one of six foreigners convicted in the first attack on the World Trade Center, which killed six people and injured more than 1,000.

Court documents say that in 1992, Mr. Ajaj, also known as Khurram Khan, left his home in Houston and attended a terrorist training camp on the Afghanistan-Pakistan border called Camp Khaldan, where he learned how to make explosives. While there, he met Ramzi Ahmed Yousef, the convicted ringleader in the bombing.

Both men were detained when they arrived at John F. Kennedy International Airport in New York later in 1992. Customs inspectors discovered that Mr. Ajaj's passport had been altered, and when they searched his bags they found an al-Qaida bomb manual, notes he'd taken during explosives courses and videotapes calling for terrorism against Americans, court papers say.

Mr. Yousef was arrested for entering the country without a visa, and was released on his own recognizance. Mr. Ajaj was later indicted for passport fraud and sentenced to six months in prison.

In a letter to a defense attorney who had protested the treatment of convicted terrorists behind bars, Assistant U.S. Attorney Patrick Fitzgerald cited an incident involving Mr. Ajaj to justify extreme security measures, including limited phone calls and separation from other inmates.

While incarcerated before the bombing, Mr. Ajaj made telephone calls to aid his cohorts in the ongoing plan to bomb the towers, Mr. Fitzgerald said in the letter. Mr. Ajaj managed to be patched through to Mr. Yousef, and the two spoke in codes.

Mr. Yousef was able to organize the bombing with a loose-knit and poorly trained crew. They rented an apartment in Jersey City, N.J., to serve as a bomb factory. One man drove a bomb-laden van into the building's parking garage Feb. 26, 1993.

Mr. Yousef was arrested in Pakistan in 1995, reportedly while staying in a guest house owned by Mr. bin Laden's family. Authorities have named Mr. bin Laden as the prime suspect in last week's massacre.

In a 1998 interview, ABC News reporter John Miller asked Mr. bin Laden whether he knew Mr. Yousef. He replied, ''Unfortunately, I did not know him before the incident. I remember him as a Muslim who defended Islam from American aggression.''

If the U.S. invokes a war against Muslim extremists, terrorism experts don't expect anything to happen in Edgefield. Terrorists more likely would concentrate on easy, high-profile targets, said Loch Johnson, Regents professor of political science at the University of Georgia.

If Mr. Ajaj's friends want him liberated, history shows they'd be prone to take hostages somewhere else and demand a trade, said Charles Staten, a senior analyst for the Chicago-based Emergency Response and Research Institute.

''That's one of the dangers of us having all of these guys in federal prisons,'' Mr. Staten said.

Reach Johnny Edwards at (706) 823-3225 or johnny.edwards@augustachronicle.com.