(CNN) -- Three people were killed and 37 injured after a bomb exploded Sunday morning in Cotabato City, Philippines, the military said.
Initial reports indicated that the Moro Islamic Liberation Front planted the bomb, which exploded at 8:30 a.m. local time in the city in Mindanao province, said Philippine armed forces Maj. Randolph Cabangbang.
The Web site of the rebel group, the country's largest Muslim separatist organization, said only that the incident was being investigated.
The bomb exploded in a small restaurant, near the Immaculate Conception Cathedral, while Mass was being celebrated, Cabangbang said. Early reports indicated that the restaurant was targeted.
"The wounded and killed were mostly soldiers," Cabangbang said.
The Moro Islamic Liberation Front has fought for decades for an independent Islamic state in the southern Philippines.
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