The Federal Bureau of Investigation is examining laptop computers linked to suspects in last week's deadly Brussels bombings as investigators work to unravel the militant network behind the attacks.
The laptops arrived in the U.S. on Friday and now are being examined by FBI experts, a U.S. government source said on Tuesday.
The Wall Street Journal reported on Monday that Belgian authorities had provided copies of laptop hard drives to the FBI. It is not yet clear whether FBI technicians have recovered any significant data from the equipment the Belgians turned over, the source told Reuters.
U.S. officials have pledged support for Belgian efforts to crack down on militants behind the March 22 suicide bomb attacks at a Brussels Metro station and the city's Zaventem Airport and other recent attacks.
The death toll from the attack on the airport, and the subsequent bombing of a rush-hour metro train, rose to 35 on Monday, excluding the three men who blew themselves up.
On Saturday, President Barack Obama said a team of FBI agents was helping investigators on the ground in Belgium.
U.S. officials have said that Belgium's security and intelligence agencies are overstretched and also hampered by internal political, financial and cultural problems, including a linguistic divide between French and Flemish speaking investigators.