Same-sex marriage may now be legal across Canada, but gays and lesbians might not experience such a warm welcome when travelling abroad, the federal government has warned.

Just days after Ottawa legalized gay marriage, Foreign Affairs says same-sex married couples could be refused entry to countries that do not accept or acknowledge gay marriage.

"We cannot take for granted that rights that are recognized in Canada will be recognized or accepted abroad," Foreign Affairs Minister Pierre Pettigrew said in a statement Sunday.

"Attempting to enter a country as a same-sex married couple may result in refusal by local officials."

The department also warns that, in certain countries, homosexual activity is illegal and if convicted a person could risk a fine, imprisonment, whipping, or even deportation and death.

Gay couples are advised to be aware of their rights and also the laws of the country they are planning to visit.

"Whether visiting or moving to another country, Canadians should always take the time to learn about the laws of the country for which they are destined before leaving home," Pettigrew added in the statement.

Canada became one of only four countries to legalize same-sex marriage when Bill C-38 received royal assent last Wednesday. The Netherlands, Belgium and Spain are the other three.

In the wake of its passage, same-sex couples lined up to get married in Alberta, Prince Edward Island and two of the territories, where provincial laws had limited marriage to a man and a woman.

Amnesty International, citing 2001 information, says homosexual activity is illegal in countries such as Grenada, India, Iran, Trinidad, and Jamaica.

Officials could refuse a same-sex married couple's visa. But they may allow them to enter as individuals.

Pettigrew's communications director, Sébastien Théberge, told The Globe and Mail the warning was prompted partly by "concerns and questions from Canadians," and the recent passage of the legislation.

"Sometimes we take it for granted of what we have, and the kind of rights we have in Canada. But it's not everywhere," he said.

Foreign Affairs is urging same-sex married couples to consult its consular affairs website www.voyage.gc.ca to ensure they know their rights and the laws of the country they want to visit.