Associated Press

LAGOS, Nigeria (AP) _ Nigeria marked 53 years of independence Tuesday with little to celebrate: Scores of families are in mourning over killings by suspected Islamic extremists, security forces are on high alert against feared bomb attacks and the government faces an internal power struggle.

Islamic militants continue to terrorize Nigeria‘s northeast despite a massive 4 1/2-month-old military campaign including aerial bombardments. Forty-three students were gunned down Sunday at an agricultural college where attackers also torched classrooms. On Monday, suspected militants attacked travelers on a main road, beheading 10 and killing another four. Last week, suspected extremists killed 143 civilians, three police officer and two soldiers in an attack on a military outpost _ one of the highest tolls from a single assault.

The Islamic uprising poses the greatest security threat in years to the cohesion of Africa’s biggest oil producer and most populous nation, a former British colony of more than 160 million people from more than 250 tribes almost equally divided between a predominantly Muslim north and mainly Christian south.

“I admit that these may not be the best of times for our nation,” President Goodluck Jonathan acknowledged in an address broadcast to the nation. Our people are divided in many ways – ethnically, religiously, politically, and materially. I cannot hide from this reality.”

He announced a “national dialogue” to heal rifts and urged unity to avoid the fate of Syria. Nigeria suffered a civil war in the late 1960s that killed up to a million people.

Jonathan spoke from Aso Rock, the presidential villa that overlooks the central capital, Abuja, which was rocked by twin bomb attacks at a stadium where Jonathan and other officials were celebrating independence day in 2010. Twelve people were killed and 17 wounded in the attack claimed by militants from the Niger Delta fighting to end injustice in southern oil-producing states where people remain impoverished while foreign oil companies and government officials enrich themselves.

Since then, Jonathan has marked independence from inside his well-guarded presidential compound, where he is expected Tuesday to cut the anniversary cake and release white doves in a traditional sign of peace.

A helicopter made reconnaissance flights over Abuja, where police were on a red alert. Celebrations are taking place across the rest of the country, where police and security forces said they were also deployed in a heightened state of alert. A police anti-bomb squad and sniffer dogs were patrolling a stadium where officials will celebrate in southern Abeokuta city, the police said.

The government negotiated an end to the insurgency in the Niger Delta in 2009 and paid off top rebel leaders. But the mass thefts of oil started by the militants continue to threaten the economy, with an estimated 200,000 barrels a day _ 10 percent of production _ siphoned off pipelines.

Analysts suggest similar negotiations and investment are needed to help end the uprising led by the Boko Haram terrorist network _ the name means “Western education is forbidden” _ which appeals to some of the millions of unemployed and ill-educated Muslim youths who feel marginalized by a government accused of massive corruption and bad governance. Boko Haram aims to overturn democracy, install an Islamic state and allow only Islamic schools in Nigeria.

Jonathan on Saturday likened the threat from Boko Haram to oil thefts, saying both are cancers that must be crushed.

In a message marking the anniversary, the United States said it “stands with all Nigerians to reject the heinous violence that continues to be perpetrated by Boko Haram and other extremist groups” and urged the government to bring the perpetrators to justice and to protect civilians.

Violence has continued unabated across central Nigeria, where deadly fights regularly erupt over politics, business, land and water rights, religion and other issues. Police said at least 11 people were killed and several homes torched Saturday in an ongoing fighting over grazing land between nomadic cattle herders and farmers. It was the seventh attack in five months on Zangang village, Kaduna state, in a conflict that began after farmers whose crops were destroyed by cattle killed two cows.

Local elders say increasing numbers of nomads are moving south and west as they flee the violence in the northeast.

Jonathan condoled with the families of victims of terrorism and vowed to spare no cost “in the quest to enable our people live without fear.”

Jonathan is personally challenged by an internal power struggle in his party and a newly formed coalition of opposition parties as the country gears up for 2015 elections. That campaign is being tainted by religious and regional rivalries with many northern Muslim governors opposed to the candidature of Jonathan, a Christian from the south. The president has sidestepped questions about whether he will run again.

Internal rivalries threaten the continued dominance of Jonathan’s party, which has won every election since decades of military dictatorship ended in 1999