WASHINGTON (AP) — The U.S. expressed concern Thursday over increased attacks on religious minorities in Indonesia, but human rights groups accused 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 this week. But recent years have seen increased reports of violence and discrimination against Christians, minority Shiite Muslims and the Ahmadiyah Islamic sect.

The bipartisan Tom Lantos Commission on Human Rights, a congressionally mandated bipartisan commission that monitors human rights, held a hearing on Capitol Hill to assess the situation in Indonesia.

The commission's Democratic co-chairman, Rep. James P. McGovern, cited figures from the Setara Institute, a Jakarta-based nonprofit group that monitors religious freedom, that there were 264 violent attacks on religious minorities in 2012, up from 216 attacks in 2010.

Senior State Department official Dan Baer voiced concern over such attacks and ineffective Indonesian government responses, saying that it threatens to tarnish the nation's reputation for religious tolerance. He also referred to a "disturbing trend" in forcible closures of churches — including 50 in 2012 alone — and of Ahmadiyah mosques.

He called for stronger police action and legal reforms to signal protection for all minorities.

But Human Rights Watch criticized the U.S. response, saying it was refusing to plainly acknowledge in public what its officials admit in private — that religious persecution is worsening in Indonesia.

"Islamic militants are increasingly mobilizing in mobs to attack religious minorities with almost complete impunity," John Sifton, the group's advocacy director for Asia, told the hearing.

An annual State Department report published last week said the Indonesian government's respect for religious freedom did not change significantly during 2012.

"The U.S. relationship with Indonesia is very strong, but in the relationship human rights is missing in a meaningful manner," said T. Kumar, international advocacy director for Amnesty International USA.

He called for the Obama administration to seek the release of more than 70 political prisoners and the publication of a fact-finding report ordered by President Susilo Bambang Yudhoyono into the 2004 death from arsenic poisoning of prominent Indonesian rights activist, Munir Said Thalib.

Rights activists allege Jakarta wants to keep the report under wraps as it could implicate Indonesian intelligence.

The Obama administration has put growing emphasis on its diplomacy and security interests in the Asia-Pacific region and says protection of individual freedom is key to its policy. As part of this "pivot," the U.S. has deepened ties with Indonesia, which aspires to have a more prominent role on the world stage. With 250 million people, Indonesia is the largest country in Southeast Asia and de facto leader of the regional bloc.

Part of the U.S. engagement has been to expand cooperation between the two militaries. In 2010, the U.S. resumed some assistance to Indonesia's notorious special forces, Kopassus, which was suspended for a decade because of its human rights record.

Baer said violations by Indonesia's military were no longer widespread, but there is limited accountability for abuses that take place. He said the U.S. is carefully watching how Indonesia handles the cases of 11 Kopassus members arrested for a March attack on a jail in which four prisoners were executed.

The Indonesian army has admitted soldiers were behind the murders that were carried out in retribution for the killing of a Kopassus soldier at a cafe a few days earlier.

Indonesia has responded to criticism on its record on religious freedom by saying religious harmony remains strong, and it's unfair to generalize all attacks on minorities as being linked to intolerance.