A mass shooting at a Nigerian church on Sunday (June 5) claimed the lives of several people, CNN reports.

The shooting took place after attackers stormed inside of the edifice, located in the city of Owo, and began to open fire. Adeyemi Olayemi, the legislator who represents the Owo constituency in the Ondo State House of Assembly, told the outlet that at least 28 people died when the gunmen rushed into the church and began “shooting sporadically.”

“I am deeply saddened by the unprovoked attack and killing of innocent people of Owo, worshiping at the St. Francis Catholic Church, today,” said Ondo State Governor Rotimi Akerdolu via Twitter. “The vile and satanic attack is a calculated assault on the peace-loving people of Owo Kingdom who have enjoyed relative peace over the years.”

While attacks led by motorbike-riding gangs are rare in the southwestern part of the country, similar attacks are more prominent in the northern region of Nigeria. The area is currently under siege by Boko Haram terrorists and gunmen known by the local people as “bandits.”

“We shall never bow to the machinations of heartless elements in our resolves to rid our state of criminals,” Akerdolu continued.

He also urged citizens not to take matters of the law into their own hands.

“I urge our people to remain calm and vigilant. Do not take laws into your hands. I have spoken to the heads of the security agencies,” Akerdolu continued via Twitter. “I have equally been assured that security operatives would be deployed to monitor and restore normalcy to Owo kingdom.”

During his statement, the governor also promised to “commit every available resource to hunt down these assailants and make them pay.”

The attack comes just one week after 31 people were killed and countless others were injured during a stampede at a church located in Port Harcourt, Nigeria.