Thailand's economy improved in April on a monthly basis due to increased activities in the manufacturing and service sectors, along with a rise in private investment, the central bank said on Friday.

According to the Bank of Thailand, manufacturing production picked up across several categories, particularly the automotive industry, while a sharp export increase in the earlier period helped drive inventory replenishment.

Private investment grew in April, mainly in machinery and equipment, while government spending continued to expand, the central bank's assistant governor Chayawadee Chai-Anant said.

However, merchandise exports and private consumption declined from the previous month, Chayawadee told a news conference.

She noted that the number of foreign tourists rose slightly in April compared to March but remained contracted on an annual basis. Tourism revenue also expanded, owing to a rise in long-haul travelers, who tend to spend more per trip.

Trade policies of major economies, tourism sector developments, and manufacturing sector adaptation in the face of structural challenges and increased competition are key issues to monitor going forward, the central bank said.