Gunmen have killed worshippers in a Catholic church in Ondo, south-west Nigeria, the state's governor has said. 

Rotimi Akeredolu called it a "vile and satanic attack" on innocent people. 

The armed men entered St Francis Xavier church in the town of Owo during a Sunday service. They fired into the congregation and then kidnapped a priest as well as some other church-goers, witnesses said.

Nigeria has experienced an upsurge in violence in recent months.

Kidnappings and attacks have been reported across the vast country.

No figures for the numbers killed or abducted in Sunday's attack have been confirmed.

But a doctor at a local hospital, quoted by the Reuters news agency, said that "several worshippers were brought in dead".

In a series of tweets, Governor Akeredolu appealed for calm and said people should not "take laws into your hands".

"We shall commit every available resource to hunt down these assailants and make them pay," he added.

No-one has said that they were behind this attack, but Nigeria is facing worsening violence by armed groups, the BBC's Chris Ewokor in the capital, Abuja, says.

Exactly a week ago the head of the Methodist Church in Nigeria was abducted along with two other clerics in the south-east of the country. 

The Methodist prelate said he paid $240,000 (£190,000) to be freed with his companions. 

Two weeks ago, two Catholic priests were kidnapped in Katsina, President Muhammadu Buhari's home state in the north of the country. They have not been released.

In March, gunmen targeted the vital rail link between Abuja and the northern city of Kaduna killing at least nine people and kidnapping dozens of others, many of whom are still being held.