Published: Oct 04, 2010 4:42 PM EDT
Updated: Oct 04, 2010 1:42 PM EDT

ROME (AP) - The Italian coast guard said Monday that it had called off the search for a pair of American balloonists who disappeared last week in the Adriatic Sea.

The search was called off after a final attempt to locate Richard Abruzzo, of Albuquerque, N.M., and Carol Rymer Davis, of Denver, had failed, said coast guard spokesman Lt. Massimo Maccheroni.

Maccheroni said that a robotic vehicle scanned the seabed of the Adriatic for any remains.

"We found nothing that could be traced to the balloonists," he told The Associated Press.

The veteran pilots were flying in the 54th Gordon Bennett Gas Balloon Race in New Mexico when contact was lost Wednesday. Race organizers said the two plunged toward the Adriatic Sea at 50 mph (80 kph) and likely didn't survive.

Since then, search and rescue teams with the Italian coast guard, the U.S. Navy and Croatian coastal aircraft crews have been scouring the Adriatic Sea. Over the weekend, divers had joined in the search.

The robotic vehicle plunged to depths of 200 meters (656 feet) Monday to photograph the seabed off Vieste, in Puglia, where the balloon was believed to have crashed.

Abruzzo, 47, and Davis, 65, won the 2004 edition of the Gordon Bennett race and the 2003 America's Challenge gas race - one of Abruzzo's five victories in that race.