BUENOS AIRES — Military ships and aircraft searched off the coast of Argentina on Friday for an Argentine Navy submarine missing for two days, officials said.

The vessel, which was patrolling off Patagonia with 44 crew members, last made radio contact on Wednesday morning, Capt. Enrique Balbi, a spokesman for the Argentine Navy, said in a television interview.

Two planes were deployed Thursday afternoon to begin searching for the submarine, the San Juan, one of three in Argentina’s fleet. Rescuers were hindered by poor visibility and they resumed the search Friday morning using vessels as well as aircraft.

The submarine’s last known location was 240 nautical miles off the coast, according to the Navy.

The San Juan was traveling from the Patagonian city of Ushuaia to Mar del Plata, in Buenos Aires province, conducting a routine security patrol. Submarines often ply the Argentine coast to detect illegal fishing.