London, Nov 8 (IANS): Two British-Iranian journalists for the UK-based Persian TV channel 'Iran International' have been warned of a possible risk to their lives, a UK law enforcement source has confirmed, according to a media report.

Parent company Volant Media said the Metropolitan Police had notified the pair of a recent increase in "credible" threats from Iranian security forces, BBC reported.

It denounced the "escalation of a state-sponsored campaign to intimidate Iranian journalists working abroad".

Iranian authorities have not commented yet.

However, they had announced sanctions against Iran International and BBC News Persian last month, accusing them of "incitement of riots" and "support of terrorism" over their coverage of the anti-government protests that have engulfed the country over the past two months.

The two UK-based channels are already banned in Iran, but a press freedom watchdog says they are among the main sources of news and information in a country where independent media and journalists are constantly persecuted.

Volant Media warned that the IRGC "cannot be allowed to export their pernicious media crackdown to the UK" and called on the British government to "join us in condemning these horrific threats and continue to highlight the importance of media freedom".

It added: "These lethal threats to British citizens on British soil come after several weeks of warnings from the IRGC and Iranian government about the work of a free and uncensored [Persian]-language media working in London," BBC reported.

UK law enforcement source would not discuss the suggestion in the Daily Telegraph that a "hostile Iranian surveillance team" was spotted outside the homes and offices of the journalists.