Bangkok’s bustling night life and the popular Phuket beach areas must brace for empty cash registers as the imposition of martial law in Thailand deters vacationers.

Visitors to the country may fall 5 percent this year, the biggest drop since 2009, after governments including the U.S. and Hong Kong advised their citizens to be cautious when traveling to the nation. Foreign arrivals dropped 4.9 percent in the first four months of 2014 from a year earlier to 8.62 million, according to the Thai Department of Tourism.

With tourism accounting for as much as 10 percent of gross domestic product, keeping hotels and shopping malls open and busy is key for Southeast Asia’s second-largest economy, famous for its ancient Buddhist temples and pristine beaches. Over the last decade, Thailand’s travel industry had been bruised as a siege of Bangkok’s Suvarnabhumi airport by protesters and political violence in capital Bangkok prompted airlines to stop services.

“It’s not good for Bangkok and not good for tourism in Thailand,” Mario Hardy, chief operations officer at the Pacific Asia Travel Association in Bangkok, which made the visitor forecast, said Monday. “Tourism is a huge income for the country, so this is not helping.”

Soldiers in the streets

Thailand’s army imposed martial law nationwide after months of political turmoil that brought down the government of Prime Minister Yingluck Shinawatra and tipped the economy into a contraction. The move is not a coup and people should not be concerned, Army Chief Prayuth Chan-Ocha said.

The military is seeking to restore order and is asking political groups to halt their protests, he said. Soldiers and military vehicles were on the streets of Bangkok, although no curfew has been imposed.

The U.S. Embassy in Bangkok and the Hong Kong government on Monday issued warnings to citizens to be cautious when traveling in Thailand, where protests began in October. (The U.S. State Department earlier issued a travel alert.) The Russian and Malaysian governments did as well.

Bangkok, which hosts more than half of the foreigners coming into the country, already posted a 14 percent decline in visitors in the first four months of this year, DBS Group Holdings Ltd.’s research arm said in a May 16 report.

The hotel occupancy rate has now fallen by about 13 percentage points compared with the third quarter of last year, while the monthly number of tourists is down by about 450,000, DBS said.

News coming out of Bangkok is making travelers like Rachel Tan and Maria Joseph Khoo in Singapore think twice about visiting Thailand.

Tan is reconsidering a trip to Bangkok with her boyfriend and her mother this Sunday, while Khoo is looking for an alternative destination after her parents objected to her plan to visit the country in June.

“I would love to go ahead with the trip,” said Tan, an events producer at Marina Bay Sands in Singapore. “But, it would depend on how the government advisory changes.”