The U.S. is expressing concern over increased attacks on religious minorities in Indonesia, but human rights groups accuse Washington of downplaying the problem as it looks to forge stronger relations with Jakarta.

Muslim-majority Indonesia has emerged as Southeast Asia's most robust democracy since the fall of longtime dictator Suharto 15 years ago. But recent years have seen increased reports of violence and discrimination against Christians, minority Shiite Muslims and the Ahmadiyah Islamic sect.

Senior State Department official Dan Baer voiced concern Thursday over such attacks, and ineffective Indonesian government responses, saying they threaten to tarnish the nation's reputation for religious tolerance.

But Human Rights Watch criticized the Obama administration's moderate response, saying it was refusing to acknowledge in public what officials admit in private — that religious persecution is worsening.