BANGKOK (AP) -- As Thailand finishes its first day under martial law, there are some questions that the military action raises. Many wonder if the arrival of soldiers in the streets of Bangkok constitutes a military coup, and how it affects people living in the Thai capital or visiting.
Here is a guide to understanding what martial law means for Thailand and the country's tumultuous political crisis:
WHY MARTIAL LAW? The army says it needs to restore order after long-running political protests that have been targeted by violence, including the use of "war weapons against the people." In the latest attack last week, grenades fired at an anti-government protest site in Bangkok left three people dead and more than 20 injured.
WHY NOW? The anti-government protest leader billed this week as the "final battle" in ousting the government. Meanwhile, thousands of "Red Shirt" government supporters were gathering on Bangkok's outskirts. The military stepped in partly to prevent clashes between the sides.
COULD THIS BE THE FIRST STEP IN A COUP? A coup is always a possibility in Thailand. The military has staged 11 successful coups since the end of absolute monarchy in 1932, but it made no immediate moves Tuesday to dissolve the country's constitution or its current caretaker government. If uncontrollable violence erupts, the military might have little choice but to step up its role in politics.
HOW DOES THIS AFFECT THE GOVERNMENT? Thailand's caretaker government remains in power, though it didn't look particularly powerful on Tuesday. Acting Prime Minister Niwattumrong Boonsongpaisan waited nearly 12 hours to respond to the army's announcement. An aide told reporters the prime minister's location was being kept secret for security reasons, and he met with Cabinet ministers in a "safe house." Cabinet ministers said the army had not consulted the government before declaring martial law.
HOW DOES THIS AFFECT ORDINARY THAIS AND VISITORS? Not much, at least for now. Life in Bangkok, a sprawling capital of 10 million people, was largely unaffected. Schools, businesses and tourist sites opened as usual. The military kept a low profile in central Bangkok. Soldiers were mainly visible around the two main protest sites and at some key intersections. Despite foreign government warnings to avoid protest areas, the mood was not tense. Some Thais posed for selfies with the soldiers.
HOW HAVE RED SHIRTS REACTED? Red Shirts have expressed no outrage, saying they could accept martial law but that they won't tolerate a coup. A move by the military toward a full-blown coup could incite the Red Shirts and lead to more violence.
MUST PROTESTERS DISBAND? The army says it will allow peaceful protests but wants to "prevent clashes between groups of protesters with different views." It has said protesters gathered in Bangkok can stay at their rally sites but are banned from marching or moving to other locations.
HOW LONG WILL MARTIAL LAW LAST? WHAT'S NEXT? The army chief says martial law will stay in place until "the country is peaceful and safe." The timeframe depends on what happens next, and whether any violence erupts. Possible scenarios:
-- Protesters go home and elections can be held.
-- The military acts as mediator and brokers a compromise.
-- Anti-government senators push ahead with plans to install an unelected prime minister, a move that would anger Red Shirt protesters.
-- A court intervenes and stages a "judicial coup" to unseat the government, another move that would fire up Red Shirts.
-- Violence erupts.
-- A full military coup is launched.
MARTIAL LAW MEASURES. Over the course of the day, the army interrupted regular broadcasting to announce various edicts and expansions of its power under martial law.
-- Protesters gathered in Bangkok cannot march outside of their protest sites.
-- Ten politically affiliated satellite and cable TV stations, including those funded by pro- and anti-government protest movements, are asked to stop broadcasting until further notice.
-- TV and radio stations should interrupt any regular programming for army broadcasts.
-- Any broadcast or publication that could "incite unrest" is banned.
-- Police should hand over reinforcements to the military if requested.
Typically, under martial law soldiers also have authority to enter and search private property and make seizures in the name of keeping peace.
THE WORLD REACTS. From Thailand's neighbors to the United States, nations watched closely as the events unfolded in Thailand. Some reaction:
UNITED STATES: U.S. State Department spokeswoman Jen Psaki said the U.S. was very concerned. We "urge all parties to respect democratic principles, including respect for freedom of speech. We expect the Army to honor its commitment to make this a temporary action to prevent violence, and to not undermine democratic institutions."
PHILIPPINES: Philippine Finance Secretary Cesar Purisima said the Thai unrest might spook investors but that trade was still flowing and supply chains still moving. "We're just cheering on the sidelines for them to resolve it. Thailand is a great country. They've shown their resilience and we're confident that this is a short-term hiccup."
INDONESIA: Foreign Minister Marty Natalegawa said his country was deeply concerned and hoped normalcy could be restored quickly. "Indonesia has consistently called for respect of constitutional process and democratic principles in order to promote national reconciliation and unity, reflecting the wishes of the Thai people."
JAPAN: Chief Cabinet Secretary Yoshihide Suga urged Thailand to resolve the disputes peacefully. "We would like to urge all relevant parties to exercise restraint and not to use violence, and we strongly hope that they can peacefully resolve the differences of their positions through democratic process and sincere dialogue." Suga said Japan will take necessary steps to ensure safety of the Japanese citizens and the companies in Thailand.
AUSTRALIA: The Department of Foreign Affairs and Trade urged all parties in Thailand to resolve their differences through peaceful democratic processes. "Thailand has Australia's goodwill and support as it tries to find ways to settle its political difficulties."
AP writers Thanyarat Doksone and Todd Pitman in Bangkok, Jim Gomez in Manila, Philippines, Niniek Karmini in Jakarta, Indonesia, and Rod McGuirk in Canberra, Australia, contributed to this report.