(Reuters) -- U.S. allies Saudi Arabia and Egypt are among 10 mostly Muslim nations whose governments impose the most curbs on religion, according to a report by the Pew Forum on Religion & Public Life.
Afghanistan's government also ranked poorly, highlighting a potentially sensitive diplomatic flashpoint as President Barack Obama sends more U.S. troops to the Central Asian country to quell a growing insurgency.
The Pew report says nearly 70 percent of the world's 6.8 billion people live in countries that have severe restrictions on religion.
The report ranked countries by two measures: government restrictions on religion and restrictions from violence or intimidation by private individuals or groups. Saudi Arabia was the only country to rank "very high" in both measures.
The first index ranked 10 mostly Muslim countries as "very high." It also included China and mostly Buddhist Myanmar.
No. 1 oil exporter and U.S. Middle East ally Saudi Arabia was ranked the most restrictive, followed by U.S. adversary Iran. Pew noted both impose limits on minority faiths and "enforce strict interpretations of Islamic law."
Egypt was also in the "very high" list and several of the countries, including Saudi Arabia, are routinely cited in the U.S. State Department's annual International Religious Freedom Report under "restrictions, abuses, and concerns."
The report said Afghanistan's constitution appeared to protect its citizens' right to choose their faith "but qualifies that measure of protection by stipulating that 'no law can be contrary to the sacred religion of Islam.'"
China was cited for restrictions on Buddhism in Tibet and on Uighur Muslims, its ban on the Falun Gong movement and its pressure on religious groups not registered by the government.
By region, the Middle East and North Africa were the most restrictive, while the Americas were the least.
The governments of sub-Saharan Africa were ranked less restrictive than those of Europe, the report said.
"The relatively high government restrictions score for Europe's 45 countries is due in part to former communist countries, such as Russia, which have replaced state atheism with state-favored religions that are accorded special protections or privileges," the report said.
Western European countries Germany, France and Austria scored above their region's medium because of laws designed to protect citizens from dangerous cults or sects, it said.
In the separate index measuring social hostilities, Muslim countries again dominated the "very high" list. They were joined by Israel and India.
"Israel's social hostilities score includes acts of religion-related terrorism and religion-related war, as well as hostilities within and between religious groups in Israeli society," said Pew researcher Brian Grim.
The regional pattern of social hostilities mirrored the government restrictions, with the Middle East and North Africa on top and sub-Saharan Africa and the Americas at the bottom. Europe was seen as hostile in this regard as the Asia-Pacific.
"The relatively higher level of religious hostilities in European societies is driven by widespread instances of anti-Semitism, tensions between Muslim minorities and secular or Christian majorities, and a somewhat general distrust of new religious groups," Pew said.