Abuja: At least 50 people including women and children were killed and others injured after gunmen attacked a Catholic church in Nigeria's Ondo state during mass on Sunday, according to media reports.

Daily Sabah reported that the attack took place in Owo, a town in Ondo state, as many worshippers gathered at the church during the morning mass on Sunday.

According to the agency, the gunmen first detonated explosives near the church altar before firing at the worshippers and killing scores of them on the spot.

The official said it is difficult to put a number to the casualties, as security operatives rushed to the scene to rescue worshippers. He said injured victims were rushed to a government-run hospital in Owo town, Xinhua News Agency.

Ondu state governor Arakunrin Akeredolu confirmed the attack in the statement.

The governor said he is "deeply saddened by the attack and killing of innocent people of Owo, worshipping at the St. Francis Catholic Church, today."

Akeredolu urged the locals to "remain calm and vigilant" as security forces are deployed to monitor and restore normalcy to the town.

President Muhammadu Buhari condemned the attack as a "dastardly act."

As of Sunday night, there had been no claim of responsibility and the motive for the massacre was unclear. Officials were still assessing the toll of the attack on Sunday, The New York Times reported.

Police said in a statement on Sunday evening said that the mass was taking place around 11:30 am, when the gunmen shot at worshipers from outside the church while other gunmen targeted people inside the building.