Somali elders have launched a fresh attempt to resolve the standoff between the US navy and pirates holding an American captain hostage in a lifeboat. Somali sources say a group of elders have taken to sea to arrange safe passage for the hostage takers. The pirates have warned the US navy, which has a warship within sight of the lifeboat, against trying to rescue Capt Richard Phillips by force. His container ship has arrived with the rest of its crew in Mombasa in Kenya Crew members hailed his bravery, saying he offered himself as a hostage in order to save them when the Maersk Alabama was attacked on Wednesday. The ship is now being treated as a crime scene and US federal agents have been interviewing the crew. The captain is now being held on a lifeboat said to be drifting about 30-45km (20 and 30 miles) off the Somali coast. Shots fired A US military official said that on Saturday the four pirates guarding him fired shots at a small navy vessel which had approached, possibly to conduct reconnaissance. No-one was hurt and the navy vessel turned away without returning fire, an unnamed US official told the Associated Press news agency. In the latest attempt to end the stand-off, elders said to be related to the pirates set sail from the northern Somali town of Eyl. US military officials confirmed fresh negotiations were under way. The BBC's Jonah Fisher in Mombasa says the main stumbling block is the pirates' demand to be allowed to return to land before returning the hostage. Earlier talks failed when US officials insisted on the pirates' arrest, the New York Times newspaper says, quoting unnamed Somali officials. Abdi Garad, a Somali pirate commander, told AFP news agency on Saturday that there was concern the Americans were "planning rescue tricks like the French commandos did". French commandos stormed a yacht on Friday to free hostages, but one captive was killed during the operation. Also on Saturday, pirates hijacked a tugboat in the Gulf of Aden. The Buccaneer has 16 crew members on board, 10 of them Italians. The crew, which also includes five Romanians and a Croat, are said to have been unharmed. Another vessel, sailing under the Turkish flag, escaped when its crew used water hoses to repel the pirates who had fired a rocket-propelled grenade into the captain's cabin. A piracy expert said the hijackings did not appear to be related to the attack on the Alabama Maersk. "This is just the Somali pirate machine in full flow," Graeme Gibbon-Brooks, founder of Dryad Maritime Intelligence Ltd, told AP. Source: BBC