Thousands of Buddhist monks staged a protest Thursday outside Thailand's Parliament to demand that the country's new constitution enshrine Buddhism as the official national religion for the first time.

The Constitution Drafting Committee, appointed by coup leaders in January, formally submitted their first draft Thursday to 12 public agencies, including the Cabinet, the interim Parliament and the Council for National Security — the government advisory board comprised of leaders of the Sept. 19 coup.

More than 3,000 Buddhist monks and other Buddhists staged a sit-in protest in front of Parliament to pressure the constitution drafters to include a clause recognizing Buddhism as the national religion. They pledged to continue their protest until their demands are met.

Many of the monks — joined by at least nine elephants — took part Wednesday in an eight-hour march from the central province of Nakhon Pathom to Bangkok.

They said that Buddhism — followed by more than 90 percent of Thailand's 64 million people — has been under threat and the recognition will guarantee it will continue to be the main religion in the country. A separatist insurgency in the country's Muslim-dominated southern provinces has claimed the lives of more than 2,000 people since 2004. Southern Muslims have long complained of discrimination in the Buddhist-dominated country.

The first draft of the constitution, made public last week, does not name Buddhism as the national religion, and says the state will protect all faiths.

Prime Minister Surayud Chulanont said he was concerned that the Buddhist protests could lead to political chaos and bloodshed.

Coup leader Gen. Sonthi Boonyaratglin, however, has backed the recognition of Buddhism as the national religion, saying he expects the drafting committee will review its decision on the issue.

The 12 agencies and the public have 30 days to propose any changes to the draft constitution, which will then be considered by the drafters.

Thursday's protest is the latest in a series of demonstrations by monks. It revives a debate dating back to the adoption of the previous constitution in 1997, when a campaign to make Buddhism the national religion was dropped amid concerns that it would divide the country.

The 1997 constitution was scrapped after the September military coup, which ousted then-Prime Minister Thaksin Shinawatra.

The new constitution is expected to be put to voters in a referendum as early as September, ahead of elections scheduled for December. Critics say anti-coup groups could mobilize their supporters to vote against the constitution, which might lead to another political crisis.