Philippine security forces killed at least nine suspected leftist rebels as they clashed Saturday in the southern Philippine province of Bukidnon, a military official said. Regional military spokesman Major Michelle Anayron told reporters soldiers under 8th Infantry Battalion encountered undetermined number of New People's Army while they were on foot patrol in the township of Lantapan. Anayron said the rebels, involved in previous robbery incidents in the region, were all under Front Committee 89. The NPA, armed wing of the Communist Party of the Philippines, has been waging a guerrilla campaign in the countryside for four decades. Military estimates placed the NPA strength at more than 5,000 men scattered in more than 60 guerrilla fronts throughout the country. 