(Reuters) – Forty policemen march two-by-two through a remote Ethiopian town drawing stares from local farmers for their incongruous high-tech stab vests, body armour and riot helmets.

"Look, they are trying to terrify us," says opposition politician Teshale Idosa, his eyes widening. "And it is working. They are terrifying. We are terrified."

The tension is palpable in the Horn of Africa nation's Oromia region ahead of national elections Sunday, with six people killed in just four weeks.

The region is home to the Oromo, Ethiopia's biggest ethnic group with 27 million out of 80 million people. The area also produces most of the coffee in Africa's biggest grower, along with oil seeds, sesame and livestock, which are all key exports.

Oromia is seen by analysts as key to the future of sub-Saharan Africa's second most populous nation, a country that is Washington's main ally in the region and a growing destination for foreign direct investment.

On the road to Midakegne, soldiers and police stop and search cars, pat people down and check IDs, sometimes taking notes. Locals often seem frightened to talk about politics.

The eight-party opposition coalition, Medrek, says two of the six dead were theirs, while the ruling party says it has lost one candidate and a policeman was killed.

Another two died when a grenade was flung into a meeting of the Oromo People's Democratic Organisation (OPDO), part of the ruling Ethiopian People's Democratic Front (EPRDF) coalition

VOTER CONFUSION

Also playing on people's nerves is the fact that Ethiopia's last national elections in 2005 ended with a disputed result. Seven policemen and 193 protesters died in street riots in the capital Addis Ababa and top opposition leaders were jailed.

The opposition argues it would sweep to power if the ruling party stopped intimidating and jailing its members. The government dismisses that accusation as nonsense and says it will win easily on its development record.

The ruling party has embarked on massive investment in infrastructure such as roads and energy. The International Monetary Fund said last month that Ethiopia would excel this year with growth in excess of 5 percent.

Many people in Oromia told Reuters they were confused about how to vote, with some towns overwhelmingly supporting the opposition coalition Medrek, and others the OPDO.

Opposition figures say the Oromo have never had any power despite the OPDO's place in the government. They see that party as controlled by Prime Minister Meles Zenawi's Tigrayan People's Revolutionary Democratic Front (TPLF) — which they say runs the other three parties in the ruling coalition.

Some farmers told Reuters that officials deny them seeds and fertilizer to force them into joining the OPDO. One man said he was fired after 20 years as a chemistry teacher because he joined Medrek. OPDO members denied the allegations.

"Our party is fully independent and Oromo," OPDO official Alemayehu Ejio, told Reuters. "We are even more popular now because of our development work."

ELECTRICITY AND WATER

In Midakegne, 40 km (25 miles) from the nearest Tarmac road, the opposition says a 23-year-old activist, Biyansa Daba, was beaten to death. The government says he died of cancer and that the opposition is trying to spoil a poll it will lose.

Merera Gudina, leader of Medrek member party, the Oromo People's Congress, is tailed on the road to the secluded town by three men in a pick-up truck. His car, and another containing Medrek activists, are stopped and searched by soldiers.

When Merera arrives and makes a speech, promising more power to the Oromo people, he is filmed and photographed by the three men while armed police watch.

OPDO officials in Midakegne repeated that Biyansa died of cancer, but three people separately approached Reuters to say he was severely beaten.

Earlier the same day, as the OPDO held a large rally in the town of Gorosole, locals told Reuters they would vote for the ruling party because they were grateful for electrification and the provision of safe drinking water to the town's school.

The ruling party often points to its development achievements. Signs of progress in Oromia since the 2005 elections are evident.

An impressive road network has been built, towns have electricity and telephone masts are everywhere.

Just as the meeting is about to reach its climax — the unveiling of the new water tap for the school — Merera and his supporters appear in two cars and drive through the crowd. They throw leaflets into the air, and at the OPDO officials.

"Look at them," shouts Yohannes Mitiku, Merera's rival for the area's parliamentary seat. "They are trying to ruin our rally because they see that people support us."

"They say we intimidate them but yet they feel free to do this," he told Reuters.

Once the tap is unveiled, people filter back to villages in the surrounding hills, their absence revealing an empty street littered with leaflets and flags.

"Yes, the OPDO have been developing Oromia," says an old man who has watched the commotion. "But it's development and repression at the same time. They can build roads to the moon but I won't vote for them until we're equal."