Updated

Village elections across the Philippines were relatively peaceful Monday but voting in some rural areas was marred by violence, including two killings, shootouts and the burning of a voting center, officials said.

Troops and police went on full security alert to avert more violence after 22 candidates and supporters died in pre-election violence, mostly shootouts, over the past month. Violence and fraud have long been an unsettling hallmark of Philippine elections.

Fifteen people were killed in village election violence in 2010 and 57 died in the 2007 elections, police said.

In the latest violence, the husband of a candidate for village chairman was shot and killed Monday by suspected political rivals in Jaro town in central Leyte province. A supporter of another village candidate was killed during a rowdy confrontation with army troops in southern Agusan del Sur province, according to police.

More than 800,000 candidates vied for chairmanships and other posts in more than 42,000 urban and rural villages called barangays — the Philippines' smallest political units, where violence and fraud are as much a concern as they are in elections for higher office.

Security was tight in about 6,000 villages considered security hotspots due to a history of electoral violence or attacks by Muslim and communist insurgents or al-Qaida-linked militants.

Although there were some violent incidents, they did not "have a significant effect on the overall peace and order situation on a national scale," national police spokesman Senior Superintendent Theodore Sindac told a news conference.

In southern Maguindanao province, unidentified men fired rifles and grenade launchers, apparently to scare off election personnel delivering ballot boxes in Buldon town. The men fled when troops arrived. Some classrooms in a Buldon school which were to be used as a voting center were burned by unidentified men, disrupting elections in the area, regional military spokesman Col. Dickson Hermoso said.

Gunmen also fired at a voting center in Midsayap town in North Cotabato province, near Maguindanao.

Many teachers refused to serve as election clerks in Maguindanao and North Cotabato amid reports of violence, officials said.

"We will not risk our lives," grade school teacher Bai Nora of Pikit town in North Cotabato told radio station DXND. "After the elections, the losing candidates will get back at us if we do not entertain their desire to cheat," she said.

In the country's worst election violence, 58 members of a political clan and media employees were shot to death in a 2009 massacre allegedly plotted by a rival clan with its armed militia to maintain its political control over southern Maguindanao province. The clan members have denied any wrongdoing. Among the dead were at least 31 media workers. It was the single worst killing of journalists in the world.