Police on Saturday found a major weapons cache hidden in a house on the outskirts of the Sri Lankan capital, and arrested 17 people who an official said were planning a major attack. The weapons haul came as the military said six soldiers were killed and another four wounded in a mine explosion blamed on separatist Tamil Tiger insurgents battling security forces in the north. A passenger ferry was expected Saturday to evacuate about 160 foreign passport holders who have been trapped by the recent escalation in fighting there. In the capital Colombo, police said they foiled a major attack on the city. Officers from the police's elite special task force, acting on a tip, raided a house in Pamunugama, a coastal town close to the country's international airport on Saturday morning, seizing weapons and explosives, police said. The haul included 8 hand grenades, 2 roadside bombs, an assault rifle, ammunition and detonators, police officer S. A. Jeewahasta told The Associated Press. The officer said 17 suspects, including two women, were being held for questioning.