By Abdisalan Ahmed
GARISSA, Kenya, Feb 17 (Reuters) - An explosion killed at least one person in a Kenyan frontier town where a presidential hopeful in the country's upcoming elections was due to hold a rally on Sunday, police said.
Residents heard a huge blast late on Saturday night in the eastern town of Garissa but police only managed to pin down the site of the explosion to a primary school field on Sunday. It was caused by an improvised explosive device (IED), they said.
Martha Karua, the only female presidential candidate in the March 4 vote and among the lower-ranked candidates by most polls, had been expected to speak at the grounds on Sunday afternoon, regional police chief Charlton Mureithi said.
"Our initial assessment reveals the man was trying to set up an IED near the dais, but killed himself as the device exploded on him ripping his body into pieces," Mureithi told reporters.
The open field also lies next to an army camp in a town that is used as a support base for Kenya's military mission in Somalia.
There was no immediate claim of responsibility for the intended attack, police said.
Karua would keep her date with her supporters in the town and would use a new venue because the primary school field was now a crime scene, officials in her campaign team said.
Kenya has experienced a spate of violent attacks, mostly in the capital and close to the Somali border, since it sent soldiers into its anarchic neighbour in October 2011 to drive out the al Shabaab Islamist rebels linked to al Qaeda.
The rebels have threatened to retaliate and have launched a series of grenade and gun attacks that have raised concerns over how secure the country is heading into the March 4 national elections, the first since tribal fighting killed about 1,200 people following a disputed presidential vote in 2007.
Garissa, a market centre for trade in camels, donkeys, goats and cattle some 200 km (120 miles) from the Somali border, has borne the brunt of the wave of attacks. The largely Muslim town has a significant ethnic Somali population.
In October, Kenyan soldiers and Somali forces seized Kismayu, al Shabaab's last big urban stronghold in southern Somalia, driving the militants out.
"Its by the grace of God that the person who was planning evil died. Many people would have lost their lives if that mission succeeded," said Abdi Jama'a, a local resident.
(Writing by James Macharia; Editing by Angus MacSwan)