Authorities on the island of Mindanao, used gunfire on Friday to disperse the protestors, killing at least one person and injuring dozens of others in the process.
Around 6,000 rice farmers had blocked off a portion of a main highway in North Cotabato province for the fourth day in a row. The demonstrators were demanding financial aid from the government after a months-long drought wiped out their crops.
One of the protest leaders told Reuters news agency that people fled to a nearby church after police used water cannon and then guns to break up the demonstration.
Cotabato police officers said around 20 police officers were also wounded in the violence.
"Any violation of national police rules and regulations shall be meted (out) with the appropriate penalty," said a statement from a police spokesman.
Over 5 billion pesos ($110 million) worth of rice has been lost in the drought, which has been linked by some to devastation caused by El Nino.
blc/kms (AP, Reuters)