Spanish officials late Sunday confirmed the identities of most of the victims of last week's tragic train wreck, identifying four as Americans.

Nov. 2 (UPI) -- Spanish officials late Sunday confirmed the nationalities of most of the people killed in last week's train wreck, identifying four as Americans.

Sixty-nine people were killed and more than 180 were injured Wednesday in a collision between trains in Toledo in central Spain.

Spain's Integrated Data Center said in a statement issued through the Superior Court of Justice of Castilla-La Mancha said that it had identified 66 of the people killed, of whom 54 were Spanish nationals and 12 were foreign nationals. The three victims remaining to be identified were also believed to be foreigners, it said, adding that it expected to identify them in the coming hours.

The four Americans represented the largest group among the foreign victims, with one person each from Argentina, Canada, the Czech Republican, France, Japan, Mexico, Portugal and Tunisia. However, there are also three missing-person reports that remained active for two Australian citizens and one Japanese citizen.

Families of 60 of the victims had been notified. Families of the three victims still awaiting identification reportedly wished to travel to Spain to personally complete the identification procedures.

"Their arrival in the country is therefore being awaited," the Integrated Data Center said.

Fifty-three of the victims were identified through fingerprints while 13 were identified through DNA analysis, and officials said the families of the remaining six identified victims would be notified "as quickly as possible."

The investigation into the cause of the crash remains ongoing.

Investigators said a Renfe AVE high-speed train collided with a stationary Iryo train about 5 miles away from Urda, in Toledo province. Both trains were traveling south from Madrid to Seville at the time of the collission.

Officials have said a computer failure had caused the Iryo train to come to a stop on the tracks and that the collision occurred after the high-speed train was permitted to continue along the same line. The crash remains under investigation.

The government of Castilla-La Mancha said following the crash, when the death toll stood at 68, that 44 of the deceased victims were on the stationary Iryo train and 24 were aboard the Renfe AVE train.

On Sunday, officials said that 31 people who were injured in the crash remained hospitalized in Castilla-La Mancha, including 13 in intensive care.