ZEPHYRHILLS, Florida (AP) - An investigation has opened into the weekend deaths of a skydiving instructor and a student, both from Iceland, who died during jumps with a group in Florida.

The two men took part with 20 other people on Saturday in skydiving jumps from a plane in Zephyrhills, north-east of Tampa, said Pasco County sheriff's spokesman Melanie Snow. They were reported missing, touching off an hours-long search on Saturday.

Ms Snow said an air-and-ground search was begun when only 20 of the 22 skydivers returned from their jumps late on Saturday morning. The bodies were discovered by spotters from the air early on Saturday evening in woods south of the Zephyrhills Municipal Airport.

Ms Snow would not comment whether the parachutes of the skydivers had opened, saying that was part of the investigation. She identified the victims as 41-year-old instructor Orvar Arnarson and 25-year-old student Andrimar Pordarson. No hometowns were given. The men did not take part in a tandem jump but two separate jumps, Ms Snow said without elaborating.

She added that the men were reported missing on their third round of jumps on Saturday about 1030am on Saturday, and that their bodies were spotted later after search teams scoured a large area, focused mostly south of the municipal airport.

She said the teams were instructed to look for the men and their chutes, one green-and-white and the parachute blue-and gray.

The authorities said the skydivers were part of a jump outing through Skydive City in Zephyrhills.