Air raids may no longer target the highlands of central Sudan, but heads still turn sharply to scan the skies at the sound of an aeroplane engine overhead.
The Nuba Mountains - once a key enclave of rebels battling the government in Khartoum - saw some of the heaviest fighting of Sudan's 22-year civil war between north and south.
However many people living in the green hills and wooded valleys at the geographical heart of Africa's largest nation fear fresh conflict is looming.
"The government bombed the school here in 2000, blowing 18 children and their teacher into nothing," said Younan Albaroud, a guerilla fighter turned politician, standing at the foot of a simple memorial at the rebuilt school.
"Peace was signed five years ago, but we worry of trouble ahead," Albaroud added quietly, speaking in Kauda, the former rebel headquarters for the Nuba region.
A 2005 peace deal ended Africa's longest-running civil war, fought by southern rebels against the Arab-dominated north over resources, religion and ethnicity.
Some two million people were killed and four million fled their homes in a war separate from the conflict in Sudan's western Darfur region.
The peace deal saw the largely Christian and black African south win regional autonomy under the former rebel leadership - the Sudan People's Liberation Movement (SPLM) - with a referendum on its potential full independence slated for January 2011.
But that vote will exclude the Nuba.
The mountains - some 48 000 square kilometres (19 000 square miles) of scattered green peaks and rain-fed farmland rising from the arid plains of South Kordofan state - are isolated pockets of southern support within the Muslim north.
"We are not part of the referendum under the peace deal," said Albaroud, the SPLM chairman for Kauda, one of several zones still controlled by the former fighters.
"But the SPLM still runs this region. The Sharia (Islamic) law of the north is not imposed here."
Instead, the future of the Nuba - and the other contested area of Blue Nile state - will be decided by "popular consultations".
But that process is ill-defined, and without set steps for either autonomy or potential secession from the north that many say they want.
They prefer the country remain united
"We are frightened we will be abandoned," said Bashir Kuku, a farmer drinking a bowl of home-brewed sorghum beer beneath a tree at Kauda's weekly market.
"If the south splits in the referendum, we will be left alone to face the north.
"In the war, we in the Nuba fought for equality in a unified Sudan -- we call it the New Sudan' -- but the south now wants independence alone."
Historically the highlands provided refuge for those fleeing slave raids, and the Nuba peoples - some 50 mainly black African ethnic groups - have much in common with those of the south.
But analysts warn the wider region of South Kordofan is a volatile mix of rival different Arab and African groups, where old enmities from the war are exacerbated by pressure on grazing land.
The International Crisis Group think tank warned last year the state could spiral into the "next Darfur," with people "polarised and fragmented along political and tribal lines."
On the ground there is little optimism.
"Some of us are Christians, some are Muslims, and some follow our African beliefs - but we live as one," said Ezekial Elamin, another farmer.
"But without the south, the northerners will take the land off us, force us to the ways of Sharia law and we will fight that."
Critics in the Nuba say the 2005 peace deal sold out key supporters of southern secession, with many in the south already itching for independence.
A September study by the Washington-based National Democratic Institute found "unwavering support for political separation" among those it questioned in the south.
"The Nuba people fear the breakaway of the south because they will be left as an isolated minority in the north, and will also be on the front line of any future north-south conflict," said Peter Moszynski, a long-time Sudan analyst who began working in the mountains during the war.
"They would prefer that the country remain united, but this option appears less and less realistic."
It is an issue many fear makes the region - already awash with automatic weapons - a likely future flashpoint.
Many Nuba fighters joined the southern army, and it is not clear where their loyalties would lie if the south separates.
"Many of the ordinary people are not yet aware that they do not have a referendum, which may be a further source of conflict when they do finally find out," wrote analyst John Ashworth in a September report from the Pax Christi advocacy group, warning the situation "could easily trigger fresh violence."
Security is already a problem in the underdeveloped region, where rule is complicated by a parallel system run by the former rebels.
"There is no development, no security, no happiness, because people see the peace implementation has not been going well," said Kamal al-Nur, a former rebel colonel, and now commissioner of the SPLM-controlled Heiban county.
"There are many militias who once fought for the government, and they are still strong with many guns."
Tensions are mounting ahead of elections due in April 2010, with reports of the reorganisation or rearming of civil war-era militias on both sides.
At the end of a wooded valley dotted with thatched huts and small farms, around 80 SPLM members cram into a rare solid brick building - the party's Political Leadership Training Institute for the region.
"We are preparing the party for the coming elections," said Ibrahim Khatib, who is running a series of 35-day courses for supporters across South Kordofan.
"We provide information on voting and campaigning - as well as lessons on the equality of religion, the importance of human rights, and the history of the oppression this region has suffered."
Some were enthusiastic that the vote would create a better future.
"The elections are our chance to elect a leadership that reflects the people of Sudan," said Nugud Yusuf, leader of a women's group.
But others in the Nuba were more cynical.
"Perhaps we can solve things through the elections," said trader Adam Arnab. "But I sadly believe the time for the gun will come again."