Buenos Aires (AFP) - Argentina's navy was hunting Friday for one of its submarines which has been reported missing off the country's south coast with a crew of 44 on board.
The navy said it had not had contact with the submarine, the San Juan, for 48 hours.
"We have not been able to find, or have visual or radar communication with the submarine," navy spokesman Enrique Balbi told a news conference.
The TR-1700 class diesel electric submarine had been returning from a routine mission to Ushuaia near the southernmost tip of South America, to its base at Mar del Plata, around 400 kilometers (240 miles) south of Buenos Aires.
The San Juan's last contact with the navy command was on Wednesday morning, Balbi said.
Argentina said it launched an air and sea search on Thursday, involving a destroyer and two corvettes.
An initial search in an area around the sub's last known position, some 430 kilometers off the southeastern Valdez peninsula, provided no clues.
Balbi said the search was hampered "because it was carried out at night and in bad meteorological conditions prevailing in the area of operations."
The navy denied a press report that there may have been a fire onboard.
Balbi appealed for caution. "I don't want to dramatize the issue. We're lacking communication and don't know what happened," he said.
"There may be a battery issue, a problem of power supply," the spokesman said, adding that navy protocol was that the submarine would surface if any power problems were detected.
The San Juan sailed 10 days ago from Mar del Plata to Ushuaia. It spent three days there before heading off on the return voyage, Balbi said.
Among those on board is Argentina's first female submarine officer, weapons officer Eliana Krawczyk, 35.
"Let us pray that nothing has happened to any crewmember. At sea they are all brothers, and a submarine carries more risk than a ship," her father Eduardo told Todo Noticias TV.
The San Juan is one of three submarines in the Argentine fleet.
Sixty-five meters (213 feet) long and seven meters wide, it was built by Germany's Thyssen Nordseewerke and launched in 1983.
It underwent a re-fit between 2007 and 2014 to extend its usefulness by some 30 years.