The Supreme Court ruling was celebrated at Gay Pride marches at the weekend in several US cities
Officials in the US south are resisting last week's Supreme Court ruling on gay marriage by refusing to issue licences to any couples - gay or straight.
Last Friday the court said marriage for all is a constitutional right.
But reports suggest some county offices in Alabama, Kentucky, Mississippi, Texas and Louisiana are trying to find ways around the contentious decision.
Many opponents of gay marriage are preparing for legal challenges over religious objections to the unions.
In Alabama, one judge is refusing to issue marriage licences to anyone, saying that state law merely says they "may" be issued by officials, not that they must issue them.
Wes Allen, a probate judge in Pike County in southern Alabama, told the AP news agency that he is "not in violation of any Supreme Court order".
"We're just going to hold the course and not issue any marriage licences," he said, adding that he believes marriage "is one man, one woman".
Gay marriage supporters gathered outside Rowan County Judicial Center in Kentucky after it stopped issuing marriage licences
In Kentucky, Rowan County Clerk Kim Davis is another official ignoring the ruling and turning gay couples away from her office.
"It's a deep-rooted conviction; my conscience won't allow me" to grant gay-marriage licences, she told AP. "It goes against everything I hold dear, everything sacred in my life."
Many officials are pointing to religious rights and freedom of speech in a bid to justify their refusal to recognise gay marriage, but some experts doubt such arguments will stand up in the long run.
On Wednesday, a federal judge in Alabama told county offices they must abide by court decisions allowing gay marriage. However, the order does not affect counties that have stopped issuing all marriage licences.
Same sex marriage is now legal in the entire US after a Supreme Court ruling striking down state marriage bans.
The ruling means all US states must grant marriage licences to gay and lesbian couples and recognise marriages that have taken place in other states.
So how did we get to this point?
One of the first couples to wed in Massachusetts
In 1996, the US Congress passed and President Bill Clinton signed the Defense of Marriage Act, a law that prohibited federal recognition of same-sex marriages.
In 2003, Massachusetts judges ruled the state constitution allowed gay marriage, and marriage licences followed shortly after that. In the following years, a handful of states passed gay marriage bans while others began working towards allowing same-sex unions - either by court order or legislation.
One high-profile ban occurred by referendum in California in 2008 after courts had previously allowed same-sex marriage.
This continued across the US until the Supreme Court heard a challenge to the Defense of Marriage Act in 2013.
What did justices have to decide in this case?
Jim Obergefell brought a lawsuit against the state of Ohio after the state refused to recognise his marriage to his late husband
The justices, who had previously stopped short of resolving the question of same-sex marriage nationally, had to consider whether or not states were constitutionally required to issue marriage licences and if states were required to recognise same-sex marriages performed elsewhere.
How many states previously allowed same-sex unions?
Before the ruling, 36 states were issuing marriage licences to same-sex couples, as well as Washington DC, which sets its own marriage laws but is not legally a state.
A referendum on gay marriage in California in 2008 put the legal status of previously performed marriages in question
A critical turning point came in October 2014, when the Supreme Court chose not to hear appeals against lower court rulings that had overturned same-sex marriage bans - expanding the legality of gay unions to many more states.
In other states, same-sex marriage has been approved either through legislation or voter referenda.
Michigan couples were briefly able to marry before a court stayed a ruling overturning its ban.
What have been the key Supreme Court rulings?
On 6 October 2014, the court turned away appeals from five states with gay marriage bans on the books that had challenged court rulings overturning those bans.
In challenging the gay marriage bans, proponents relied on a 2013 Supreme Court ruling in the case of United States v Windsor.
Edith Windsor was the plaintiff in the last gay marriage case at the Supreme Court
In that case, the court overturned the Defense of Marriage Act (Doma), which barred the federal government from recognising same-sex marriages.
Under Doma, for example, individuals in same-sex marriages were ineligible for benefits from federal programmes such as the Social Security pension system and some tax allowances if their partners died.
Another key case, Hollingsworth v Perry of 2013, was filed by two lawyers, Theodore Olson and David Boies, working together on behalf of their California clients, Kristin Perry and Sandra Stier and another couple, Jeffrey Zarrillo and Paul Katami.
They argued that the Supreme Court should strike down a state law, called Proposition 8, which stated that marriage is between a man and a woman. The law, approved by California voters in 2008, overrode a state Supreme Court decision that allowed for same-sex marriage.
What is next?
Marriages will continue as before in the 36 states. The remaining states will have to issue licences, although it is unclear how long they have to comply with the court's ruling. However, there were reports of court clerk offering licences only an hour after the Supreme Court decision.
On Friday morning many Americans wondered if the US Supreme Court would announce its decision on whether states could prohibit gay couples from obtaining marriage licences.
When news of the court's landmark decision affirming gay marriage rights in all 50 states broke, celebrations quickly erupted outside the court building - and on Twitter.
From celebrities...
Business leaders...
And politicians...
Some of the political reaction wasn't as joyous, however. Republican presidential candidate Mike Huckabee condemned the ruling.
Others took the opportunity to point out that it's been an interesting week for flags in the US.
And a White House agency offered what it saw as an appropriate photo.
