COLOMBO, June 22 (Reuters) - Sri Lankan tourist arrivals fell 40 percent in May from a year earlier, the island's tourist board said on Friday, citing renewed civil war between the state and Tamil Tiger rebels. Arrivals are now down 23.4 percent during the first five months of the year compared to the same period in 2006, and many hotels have very low occupancy rates and are sharply discounting rooms in a bid to lure clients. "It is the situation in the country, travel advisories and the closure of the airport," S. Kalaiselvam, director general of the Sri Lanka Tourist Board, told Reuters, referring to the night closure of the island's only international airport following Tamil Tiger air raids on fuel installations nearby. The government has vowed to reopen the airport at night from early July. According to Central Bank data, earnings from tourism fell by 14.8 percent between January and April year on year to 130.8 million dollars. A number of foreign embassies have advised nationals to avoid north and east Sri Lanka amid an escalating new chapter in a two-decade civil war that has killed nearly 70,000 people since 1983 and around 4,500 people since last year alone.