A manhunt is underway in Nigeria after one of the West African country’s traditional monarchs was murdered in his palace and his wife was kidnapped on Thursday evening, local authorities say.

Segun Aremu, a retired army general and monarch whose title is the Olukoro of Koro, was shot dead in his palace in the country’s southwest—a region that’s seen a recent horrifying uptick in kidnappings, with criminals demanding hefty ransoms from loved ones.

Local authorities say the identities and whereabouts of the attackers are unknown. There has been no notice given on a potential ransom for Aremu’s wife, reportedly puzzling investigators.

The kidnapping and killing come after some locals have called on the national government to declare a state of emergency to address the spike in crime. Africanews reported that more than 1,800 people have been abducted in Nigeria since President Bola Tinubu took office in May.

AbdulRahman AbdulRazaq, governor of Kwara state, said the slaying of Aremu was “reckless, shocking, and abominable.” In a statement, he vowed to catch those responsible.

“We will certainly get the perpetrators and ensure that this is their last crime against humanity,” he said. “My profound condolences go to the people of Koro. Our hearts are broken, and we stand by them at this time and always.”

In addition to Aremu’s wife, authorities said three others were kidnapped from the palace, but their identities have been withheld.

The violence follows the murders of two traditional rulers in nearby Ekiti State earlier in the week. Kidnappers also abducted five schoolchildren and four teachers in Ekiti, demanding a ransom of more than $100,000 for their return.

Elsewhere in the country, a senior government official was kidnapped Wednesday night outside the capital, not far from the home of six sisters who were abducted for ransom—with one killed after loved ones didn’t pay up fast enough, the BBC reported.

P.M. News, a Nigerian newspaper, reported Friday that President Tinubu condemned the killing of Aremu and “directed security operatives to ensure the rescue” of those kidnapped from the palace.