Naval vessels searching Swedish waters for a suspected foreign submarine are focusing on a bay near the capital Stockholm on the fifth day of the biggest such operation in years.
Ships equipped to detect submarines are among at least five vessels searching Ingaro Bay.
One Swedish newspaper said that a ship had "made contact" but there was no official comment on the report.
Russia has denied that any of its vessels are involved.
A Russian oil tanker has been sailing in international waters nearby, raising suspicion that it was there to help a submarine in difficulty.
Russia has several submarines based in Kaliningrad, a Russian enclave bordered by Poland and Lithuania and facing out to Sweden, as well as a much bigger force near Murmansk on the Kola Peninsula.
The supreme commander of Sweden's armed forces, Sverker Goransson, told a news conference that it was "too damned bad that someone or some thing is inside our territory in this way", indicating that the military was convinced that something was present.
He said there had been further observations in the past 24 hours and the military would comment on them later.
In another development, Swedish Prime Minister Stefan Lofven announced his government would increase spending on defence in its budget on Thursday.
"We agree on a broad basis between many parties in Sweden in the Swedish parliament that we need to increase our capacity, meaning that we need to put more resources into defence," he said on a visit to the Estonian capital Tallinn.
Among ships in Ingaro Bay were the Trosso, the Stockholm and the Visby, which have advanced equipment to look for submarines, Swedish media report.
Reporting the "contact", Dagens Nyheter said it could not reveal its source for the information or explain exactly what the military meant. Swedish public radio reported that the military had not commented on the report.
Earlier, the military admitted giving out misleading information about the location of a picture widely circulated since the search began.
A Swedish military spokesman said the wrong information had been released about the grainy photo, which shows a dark object at sea, surrounded by foam, "so as not to aid a foreign power".
An order that private boats stay at least 10km (six miles) away from the search operation was removed on Monday but airspace above the search area remains closed to civilian flights at low altitude, Swedish radio reports.
Soviet submarine sightings during the Cold War caused security alerts in Sweden in the 1980s.
There have been three reported sightings of a submarine west of the capital, Stockholm, since Thursday.
Local media said Sweden had also intercepted a distress signal in Russian.
Meanwhile, a man whose presence in the search area raised suspicions has turned out to be a Stockholm old age pensioner out fishing for trout.
Speaking to Expressen newspaper, "the man in black" said: "I saw there were a lot of military ships out there... A friend called and told me that I was the picture in the newspaper."
Russia's official government newspaper, Rossiiskaya Gazeta, questioned whether there was any submarine at all.
"Either Sweden's echo location equipment is working badly or, as the old saying goes, the eyes of fear see danger everywhere," it remarked.
A Russian-owned oil tanker, the Concord, has been circling near Swedish waters for days, giving rise to suspicions that it is there to resupply a submarine.
However, Anders Nordin at the Swedish Coast Guard told Swedish news agency TT that its journey was consistent with normal tanker movements.