DUBAI (Reuters) - Saudi Arabia has made little progress in removing textbook content that promotes violence and hatred towards religious minorities and others, a U.S. government watchdog said, encouraging Riyadh to take the issue more seriously.

Saudi Crown Prince Mohammed bin Salman, currently on his first visit to the United States as heir apparent, has promised to promote a more moderate form of Islam under plans to modernize the deeply conservative Muslim kingdom.

The Saudi education minister last week said the country was revamping its education curriculum to eradicate any trace of Muslim Brotherhood influence and dismiss anyone working in the sector who sympathizes with the banned group.

In a new study of select textbooks in use in Saudi Arabia, the U.S. Commission on International Religious Freedom (USCIRF) said in a statement on Saturday it had compared twelve 2017-2018 high school religion textbooks with versions from 2012-2014 and found that the current books contained not only numerous intolerant and “inflammatory” passages but also several passages specifically thought to have been removed from earlier books.

It said examples of intolerant content included passages extolling jihad - or holy war - as fighting against non-Muslims, prescribing execution of apostates and those who mock God or the Prophet Mohammad, and demeaning non-Muslims and warning Muslims against associating with them.

The Saudi government information office did not immediately respond when asked for comment.

The USCIRF review matches a report last year by Human Rights Watch that said a review of religion books produced by the Education Ministry for the 2016-2017 school year found that the curriculum promotes intolerance.

The commission said such passages demonstrate how little progress has been made over the last 15 years in textbook reform in the kingdom - whose late King Abdullah bin Abdul-Aziz launched an overhaul of state schools and universities in 2005 as part of reforms designed to ease the influence of religious clerics, build a modern state and create jobs.

“USCIRF urges (the U.S.) Congress and the administration to make textbook reform a priority in its engagement with the Saudi government, especially in light of that government’s progress in other areas of reform,” USCIRF Chairman Daniel Mark said.

Prince Mohammed is visiting the United States to attract investment and drum up support for domestic economic reforms.

On a visit to Britain earlier this month, the crown prince met the head of the Anglican church in London and promised to promote interfaith dialogue as part of reforms.