The attacks, among the bloodiest by the New People´s Army (NPA) in months, also left five soldiers wounded, a military statement said.[break]
The first group of soldiers were on their way to meet pro-government militiamen when they hit a landmine planted by the NPA, it said.
The rebels then opened fire on the soldiers, leaving eight dead and one in critical condition.
They then carted off seven of the soldiers´ rifles.
Troops rushing to the aid of the first group were hit by another landmine and ambushed by the rebels, killing one more soldier and wounding four others.
The attacks took place near the town of Kidapawan on the southern island of Mindanao.
"This criminal act of the NPA in using landmines has to stop," the local army commander, Colonel Marcos Flores, was quoted as saying.
The military has accused the rebels of using landmines even though the Philippine government ratified an agreement banning the use of such devices in 2000.
The rebels have previously said their devices are different from military landmines and are not covered by the ban.
The NPA, the militant wing of the Communist Party of the Philippines, has been waging an armed campaign in the Philippines since 1969. At least 30,000 people have been killed according to the government.
While the NPA ranks have declined to about 4,000 fighters from a peak of 26,000 in the 1980s, the rebels are still capable of mounting deadly attacks, especially in rural areas where isolated military and police units and businesses are targeted.
President Benigno Aquino had been aiming to end the rebellion before his six-year term expires in 2016, but the government said in April that peace talks had collapsed.
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