Federal officials intensified their pursuit of terrorist financing today with the arrests of four brothers in Dallas who investigators said used their computer business to funnel money to a leader of the Islamic militant group Hamas.
The four brothers, including one who led an Islamic charity in Texas that the authorities say was a front group for terrorist financing, also illegally shipped computer goods to Libya and Syria despite their official designations as state sponsors of terrorism, prosecutors said.
Officials filed charges against a fifth brother, the brothers' company and a Hamas leader overseas and his wife. The charges were part of a flurry of activity by federal officials, who have vowed to shut down the money pipeline between American financiers and global terrorists.
On the same day, Customs Service agents, in a separate case in the Detroit area, arrested six men and searched 10 businesses and residences in an investigation into an Islamic "hawala," or money exchange, which the authorities say illegally funneled as much as $50 million a year to Yemen.
A day earlier, officials in the Buffalo area charged a civic leader and two relatives with illegally sending hundreds of thousands of dollars to Yemen, and less than two weeks ago federal agents in Boston raided a computer company suspected of having financial ties to Al Qaeda associates.
Law enforcement officials said they expected to announce a break in yet another major terrorist financing investigation in a handful of cities within the next several days.
Arab-American leaders said the arrests and warrants would fuel the perception among Islamic residents that legitimate charities and businesses were being singled out for harassment by law enforcement officials.
Tamir Ayad, executive director of the Dallas-Fort Worth chapter of the Council on American-Islamic Relations, said of the brothers who were arrested: "These are very well-known, well-liked, well-respected, generous people. I think these charges are a terrible mistake, and we're really just hoping they get their fair day in court to prove their innocence."
But government officials said they had strong evidence to back up the criminal charges and warrants in all the recent cases. After months of slow going and turf fights among agencies, officials said the developments in the last few days showed that investigations were finally coming to fruition.
"What you're seeing is the culmination of sometimes long-term investigations into terrorism financing," said a senior Justice Department official who spoke on condition of anonymity.
At a news conference in Washington announcing the Dallas arrests, Attorney General John Ashcroft and Robert S. Mueller III, director of the F.B.I., vowed to pursue terrorist financiers as aggressively as the terrorists themselves.
"The war against terrorism is a war of accountants and auditors, as well as a war of weaponry and soldiers," Mr. Ashcroft said.
The Dallas case hinges on financial connections that prosecutors say they have established between a Dallas computer company called InfoCom and Mousa Abu Marzook, a former chief of Hamas's political bureau who is accused of helping to coordinate terrorist attacks by Hamas against soldiers and civilians in occupied territories.
In 1995, the United States made Mr. Marzook a "specially designated terrorist," banning anyone in the United States from financial dealings with him.
In 1997, the Justice Department deported Mr. Marzook to Jordan after jailing him for 22 months. His release ended what had become an embarrassing case for the United States and for Israel, which had requested his extradition after he was detained in the United States. Each nation sought to keep him in jail but failed to produce persuasive evidence of his complicity in Hamas's attacks. So as part of an agreement with the Justice Department, Mr. Marzook relinquished his permanent resident status in the United States and said he would not contest terrorism accusations that had prompted his detention.
Mr. Marzook, who could not be reached for comment, always insisted that his fund-raising activities were separate from Hamas attacks.
A federal indictment returned in Dallas today charged that Mr. Marzook and his wife, Nadia Elashi, invested $250,000 in InfoCom in the 1990's and that the Internet services company, run by her five cousins, secretly funneled profits to Mr. Marzook.
The indictment charges Mr. Marzook, his wife, the five Elashi brothers and their company, InfoCom, with conspiracy, money laundering, dealing in the property of a designated terrorist, illegal export and making false statements. The charges carry possible sentences of 20 years or more in prison and $7.2 million in fines.
The indictment does not say how much money prosecutors believe InfoCom funneled to Mr. Marzook, and it stops short of charging that the money was used specifically to finance Hamas or terrorist operations.
But Mr. Ashcroft drew a link between one brother, Ghassan Elashi, vice president of marketing for InfoCom, and Holy Land Foundation for Relief and Development, a charity whose board Mr. Elashi leads.
Holy Land, which was designated a terrorist support group last year and had $5 million in assets frozen because of its support for Hamas, is in the same industrial park as InfoCom in the Dallas suburbs. Mr. Ashcroft today called Holy Land "the North American front for Hamas."
Rita Katz, director of the Site Institute, a Washington nonprofit group that investigates terrorism, said the Dallas indictment was "the first time we've seen a criminal indictment of a Palestinian terrorist organization."
Tax records show that Mr. Mazook's efforts to establish a financial infrastructure to support Hamas predate the founding of InfoCom, Ms. Katz said. She said Mr. Marzook began creating the financial infrastructure that supported Hamas in the late 1980's, when he moved to Louisiana to attend college.
Mr. Marzook not only gave the seed money to establish InfoCom, but also provided $210,000 in 1992 to help establish the Holy Land Foundation, according to tax records.