AFP KANO, Nigeria — Suicide bombings at two police stations Monday killed at least two people in the northwestern Nigerian city of Sokoto, the historic seat of Islam in the country, officials and residents said.

Separately, police guarding a home belonging to Vice President Namadi Sambo came under fire from gunmen in the northern city of Zaria, leaving one civilian dead. No one lives at the house, which is undergoing repairs from damage inflicted in post-election riots last year.

Boko Haram Islamists, responsible for scores of deadly gun and bomb attacks in recent months, are suspected of having hideouts in Sokoto, but the group has rarely struck within the city.

A Red Cross official said the explosions at the Yan Marina police station in the city centre and the Unguwar Rogo station were both caused by suicide bombers. "A policeman and woman were killed in the bombings. Thirty people were injured, mostly around the market in the Yan Marina neighbourhood," said the official who requested anonymity.

A senior police officer, who did not want to be identified, said the bomber approached the station in a vehicle packed with explosives and was denied entry at the security gate, where the vehicle then blew up.

While there was no immediate claim of responsibility, Boko Haram has repeatedly targeted police across northern Nigeria, where most of its attacks have been carried out.

The city is home to Nigeria's top Islamic leader, Mohammed Sa'ad Abubakar, the current Sultan of Sokoto.

The radical Islamist group has long stated its loathing for Nigeria's traditional Muslim leaders, saying they have betrayed the faith by subjecting themselves to the country's secular government. Boko Haram has said it wants to create an Islamic state in Nigeria's mainly Muslim north, where, in the pre-colonial era, there was a powerful Islamic empire headquartered in Sokoto.

Most residents in Nigeria's southern half are Christians, and some analysts have warned that Boko Haram is trying to spark a religious war in Africa's most populous country.