Suspected al-Qaida-linked militants killed two unarmed soldiers involved in the construction of a school in the southern Philippines, officials said Sunday. The two soldiers, who belonged to an army engineering brigade, walked off a school construction site in Tipo Tipo township on the predominantly Muslim island of Basilan to buy cigarettes when they were fired upon by two suspected Abu Sayyaf gunmen late Saturday, navy Rear Admiral Alex Pama said. Government forces are hunting the attackers. Pama said the attackers may have thought the soldiers had guns they could steal. ''This is pure murder of unarmed noncombatants who were helping the town build a school,'' Pama told The Associated Press by telephone. American troops have helped provide weapons, combat training and intelligence since 2002 to Filipino soldiers battling the Abu Sayyaf. U.S. officials have hailed Basilan as a model after U.S.-backed offensives against the Abu Sayyaf fostered a period of relative calm in the province of more than 300,000 people. The Abu Sayyaf, which has about 400 fighters, is on the U.S. list of terrorist organizations because of its al-Qaida links and for perpetrating terrorist attacks, including against Americans. The group and its allies have turned to kidnappings in Basilan, about 550 miles (880 kilometers) south of Manila, and outlying provinces to make money. This has raised concerns among Philippine and U.S. security officials that ransom payments could revive the group.