A cruise boat carrying up to 150 people capsized Thursday night off the coast of Bahrain, drowning at least 57 people, officials said. Interior Ministry spokesman Colonel Tarik al-Hassan told Al-Jazeera television that 67 people were rescued. However, the media director of the security department, Maj. Mohammed bin Deinah, said 70 people had been rescued. There was no immediate explanation of the discrepancy. Coast Guard commander Youssef Al-Katem said 13 people were missing. "God willing, there will be survivors," he told a news conference Friday. Strong winds were hampering the rescue operation, bin Deinah said. Al-Hassan said not all the identities of the 57 dead were known as many of them did not carry identification papers. He said the exact number of passengers was not known because some left the boat before it sailed. Al-Hassan said he could not give the reason for the capsizing. There might be several factors that contribuited to the accident. An investigation was under way, he said. The official Bahrain News Agency said the boat was on an evening cruise that was to last several hours. It overturned less than a mile off the coast, it added. Television footage showed the boat, al-Dana, capsized but not sunk, with rescue workers walking on its brown hull. US helicopters and divers joined the rescue and recovery operation launched by Bahrain's Coast Guard. Bahrain, a tiny island nation on the western side of the Persian Gulf, is the home of the US 5th Fleet. TV images showed rescue workers taking bodies wrapped in white sheets off a small dinghy. Men carried the bodies away in blankets or on stretchers, while boats with flashing lights moved in and out of port. Scores of officials and relatives waited in the harbor watching the rescue operation. Some helped the rescue workers. Television footage also showed survivors, appearing in shock and their hair still wet, squatting on the floor of a hospital. Many of them covered themselves with blankets. One male survivor was shown being treated for head cuts. Survivors hugged each other. Some had blood streaming down their faces. Several wept uncontrollably as friends and relatives tried to calm them. Some survivors needed assistance as they disembarked from a rescue boat that brought them to shore. Prime Minister Sheik Khalifa Bin Salman Al Khalifa visited survivors in hospital. There was no indication of what caused the boat to capsize in what appeared to be perfect weather conditions in the area. The boat's owners, according to Bahrain television, said overloading could have caused the boat to capsize. Al-Katem, the coast guard chief, said an investigation was underway. However, terrorism was ruled out by a senior interior ministry official who spoke to The Associated Press on condition of anonymity because he is not authorized to speak to the media. "I rule it out 100 percent," said the official. The passengers were thought to be a mix of Bahrainis, nationals of other Gulf Arab nations and Westerners. Health Minister Nada Haffadh told al-Arabiya television that survivors who arrived at hospitals included nationals of India, South Africa, Singapore and Britain. She later told Bahrain television that a total of 24 people were hospitalized and that other survivors were released on arriving at the shore. Information Minister Mohammed Abdul-Ghafar, interviewed on al-Arabiya, said the passengers included 25 Britons, 20 Filipinos, 10 South Africans and 10 Egyptians. Sheik Rashid bin Abdulla Al Khalifa, the Interior Minister, said most of the boat's passengers were employees of a Bahrain-based company. "So far, the (rescue) operations continue. God willing, there will be more survivors rescued," he said in a telephone interview aired on Bahraini television. Al-Katem, the coast guard chief, said there were 150 guests at a dinner party aboard Al-Dana. The guests, he said, ate their dinner while the boat was still docked and that up to 20 of them disembarked before it sailed. He said the first word on the accident came from survivor Khalil Mirza, who alerted authorities from his mobile telephone saying the boat suddenly listed. One of only three Bahrainis invited to the dinner party, Mirza said the boat listed as it made a left turn soon after it left the harbor. "People were scared in the water," he said. "They were fighting with each other and screaming." The Bahrain agency said Bahrain's coast guard boats arrived at the site of the stricken vessel minutes after word of the accident arrived. It quoted Interior Ministry spokesman Maj. Mohammed Ben Dayna as saying it was too early to establish what caused the boat to capsize. A US Navy spokesman in Bahrain said American helicopters and divers were headed to the site. "We're sending divers, small boats and a helicopter right now," said Cmdr. Jeff Breslau. A pair of helicopters could be seen from the shore flying low over the site of the stricken boat. Rescue teams on small boats could also be seen using flash lights to help them search for survivors during the night.