Relatives of two Iranian journalists held by US troops in Iraq have gathered outside the British Embassy in Tehran, asking the British Government to facilitate their immediate release.
The embassy has been the site of a number of rallies recently
After meeting a top UK diplomat, the relatives said the British were convinced that both Soheil Karimi, 31, and Saeed Abutaleb, 34, were genuine reporters and promised to follow up the case.
"We are optimistic... we hope they will be released soon," Mr Karimi's cousin, Iraj Karimi, was quoted as saying by Reuters news agency.
The UK Foreign Office declined to comment on the case.
US forces arrested Mr Karimi and Mr Abutaleb on 1 July for "security violations", saying the pair were acting suspiciously.
Iran has repeatedly said that the two men were making a documentary about life in Iraq, demanding their immediate release.
"We called on the British officials to help them and not let them be harmed because of political difficulties between Iran and America," Mr Abutaleb's brother, Vahid, said.
He added that the meeting with Matthew Gould, the second highest ranking
British diplomat in Tehran, gave the relatives a new hope that the issue would soon be resolved positively.
"He (Mr Gould) said they (the British) were confident they were journalists and had told the Americans this," Vahid said.
Earlier on Monday, about 20 family members gathered in front of the embassy, condemning the arrests.
"It has been 48 days since they were arrested by the US forces, and still I have not heard anything," Mr Abutaleb's wife told the French news agency, the AFP.
A US-led coalition spokesman had said earlier that the pair was arrested when "filming coalition activity and facilities".
"They claim to be journalists, but they were certainly not acting in a journalistic capacity when they were arrested," the spokesman added.
The United States has had no embassy in Tehran since the Islamic revolution in 1979.