Polls have opened in Kyrgyzstan for a constitutional referendum that could shift key powers from the president to the prime minister and effectively outlaw same-sex marriage. Voters in the mostly Muslim former Soviet republic will approve or reject the entire package of 26 proposed amendments with a single "yes" or "no" vote. Among other things, passage of the government-backed referendum would remove the statute of limitations on some criminal offenses and hand the authorities the power to revoke citizenship in some cases.