MADRID, July 29 (AFP) - Police investigating the March 11 bombings of four commuter trains which killed 191 people in Spain's worst attack have made a new arrest, a man thought to be Moroccan, the justice ministry said Thursday.
The suspect was arrested in Carabanchel, a working-class suburb of Madrid, on Wednesday, a ministry statement said.
He was carrying a false Portuguese identity card but was "apparently of Moroccan origin," it said.
It said police were still trying to identify the suspect, but they had already established that several hours before the attacks, he visited the house in Chinchon, about 30 kilometres (18 miles) from Madrid where police believe the bombs were put together.
Under Spanish law, the judge heading the inquiry, Juan del Olmo, has three days in which to lay preliminary charges against the suspect and lock him up or he must be released.
A total of 19 people, most of them Moroccan, are being held over the attacks, including two outside Spain. Six suspects are on the run and seven others blew themselves up in a Madrid apartment in April to avoid capture by the police.