Forced marriage figures 'may not reflect full scale of abuse'
More than 1,000 possible forced marriage cases were reported to authorities last year, official statistics show.
A specialist unit gave advice or support in a total of 1,220 instances in 2015 - equivalent to three a day.
Some 329 of the cases - more than one in four - involved victims who were under 18, while more than one in three (35%) were aged between 18 and 25.
The majority (80%) involved female victims.
The figures related to the activities of the Forced Marriage Unit (FMU) , which was launched in 2005 as part of efforts to tackle the practice.
A joint Home Office and Foreign Office report published on Tuesday warned that the findings may not reflect the full scale of abuse.
It said forced marriage " is not a problem specific to one country or culture".
Since it was established the FMU has handled cases relating to more than 90 countries across Asia, the Middle East, Africa, Europe and North America.
In 2015, the unit handled cases relating to 67 "focus" countries to which a victim was at risk of being taken to, or had already been taken to.
The report said the five highest volume countries in 2015 were: Pakistan - 539 cases (44%); Bangladesh - 89 cases (7%); India - 75 cases (6%); Somalia - 34 cases (3%); and Afghanistan - 21 cases (2%).
In 2015, 175 (14%) of the cases handled by the FMU had no overseas element, with the forced marriage activity taking place entirely within the UK.
The total number of cases in which the FMU gave advice or support via its public helpline and email services represents a fall of 3%, or 47 cases, compared to the previous year.
This fall continues the general downward trend seen since 2009, the report said, adding: " It is important to note that information on forced marriage has become more widely available, and advice on forced marriage is also provided by charities and non-governmental organisations as well as the FMU.
"Since it was established in 2005, the FMU has worked with a range of organisations and professionals to increase their ability to support victims and potential victims.
"The fall in calls to the FMU in recent years may reflect this."
The FMU received approximately 350 calls per month last year, although this included repeat calls and those not relating to forced marriage.
The report added: "These statistics only represent the cases that have come to the Forced Marriage Unit. Forced marriage is a hidden practice and as a result, the figures may not reflect the full scale of the abuse."
In 2014, the Government made forced marriage a criminal offence.
A forced marriage is defined as one in which one or both spouses do not consent to the marriage and violence, threats or any other form of coercion is involved.
Coercion may include emotional force, physical force or the threat of physical force and financial pressure.