While world attention remains riveted on the drama of 276 schoolgirls missing since their abduction by a violent Islamist sect in mid-April, scattered bombings in the month since — including twin car blasts Tuesday that killed at least 118 people in the city of Jos — have spread alarm across the country and raised new concerns about tensions between Christians and Muslims in this diverse nation of 175 million.

Witnesses described seeing bodies torn apart and consumed by flames in the double blast at a busy bus station in Jos, the capital of Plateau state. The state lies in a central region that splits Nigeria’s mostly Christian and more fertile south from the mostly Muslim and more arid north, where Boko Haram militants have spread terror for five years.

The group did not assert responsibility for Tuesday’s attack, but the blast resembled other recent bombings in outdoor markets and bus stations, including two explositions that killed more than 120 people in this capital city, one that killed 25 in the northern city of Kano, and one in a village in Borno state, the region where the girls were kidnapped. Boko Haram has asserted responsibility for some of the attacks.

President Goodluck Jonathan issued a statement late Tuesday expressing sympathy for the victims of the latest attack. In the statement, he “assures all Nigerians that the government remains fully committed to winning the war against terror, and [that] this administration will not be cowed by the atrocities of enemies of human progress and civilization.”

The Nigerian Senate on Tuesday extended a six-month state of emergency in Borno and two other northern states, and government spokesmen expressed confidence that Nigeria’s security forces could handle the menace of Islamist militants. The government has reluctantly accepted Western technical and security support in searching for the abducted girls and their captors, including aerial surveillance by drones.

The central city of Jos was the location of twin bombings Tuesday. No one has taken responsibility for the explosions, but the Boko Haram militants have been behind a number of scattered bombing in the month since the abduction of 276 Nigerian schoolgirls. (Reuters)

“Our troops are out there, and our armed forces have sufficient capacity to do the job,” a government spokesman, Mike Omeri, said in an interview Monday. The international assistance, he added, only “complements” national efforts. “The effort will still be largely driven by Nigerian forces,” he said.

But the deadly bombings since the mass kidnapping, many in densely populated areas and some appearing to target Christian communities, have highlighted the government’s continued failure to curb Boko Haram’s growing reach, which now extends far beyond the group’s stronghold in the rural northeast. Many officials in the north are calling for negotiations with Boko Haram, which has made shifting demands in return for releasing the girls.

The rash of attacks, coupled with the government’s continued failure to find the girls and their captors, has intensified public criticism of the government and spawned a barrage of opportunistic faultfinding from the main opposition party, which hopes to topple Jonathan in elections next year. Meanwhile, official efforts to rally public support have been dampened by missteps such as Jonathan’s abrupt cancellation of a visit to the girls’ village last weekend.

“We were all expecting him, and we were very disappointed. We are much more skeptical now,” said a district leader in the area where the girls were abducted, speaking by telephone on the condition of anonymity for fear of reprisal. “We just want our daughters to come back alive and healthy, whatever it takes.”

In a public park in Abuja, where a group of protesters has been gathering every day for weeks, relatives of some of the missing girls spoke Tuesday of their growing frustration at the lack of progress. One man said that his niece had jumped off a truck and fled to safety as the militants sped away from her school but that four other girls in the family could not escape.

“We don’t know where they are or what is happening to them. We have been given no information, and the government is doing nothing,” said the man, Pudza Habila, 43, a government employee.

At the outdoor Nyanya Market on the outskirts of the capital, there were few customers Tuesday in a maze of tents and stalls where car bombings occurred April 14 and May 2. Near the site of one blast, where the twisted hulks of charred vehicles still rested, vendors squatted next to piles of sneakers and umbrellas. They had once felt relatively immune to the wrath of the Islamist militants; now they feel vulnerable and angry.

“We are told that Boko Haram did this, but what did anyone here ever do to offend them?” demanded a 32-year-old shoe seller named Darlington, whose shack was damaged in the first blast. “Everyone is scared, both Christians and Muslims alike. These attacks are giving Nigeria a bad name now, but it is an international problem. The only way to suppress the power of these terrorists is to eradicate them from all of Africa.”