The Bishop of Liverpool has spoken of his shock after a knifeman attacked a children's Taylor Swift-themed dance class in Southport, just north of the city. 

Two children were killed and six children and two adults critically injured in the attack shortly before midday on Monday. The school holiday club had been fully booked with 25 children aged six to 11. A 17 year old is being questioned by police in connection with the attack. 

Local churches have opened their doors for members of the community in need of a quiet space or someone to talk to.

The Bishop of Liverpool, John Perumbalath, said the tragedy had shocked the "quiet" community of Southport. 

"Today, as we have more information about the horrific events in Southport our prayers are with the family and friends of the murdered children. May God comfort the bereaved and support them at this difficult time," he said. 

"We also pray for those who remain critically injured in hospital asking God to surround them with love.

"This tragedy has shocked a quiet community and we pray for them. Churches across Southport are open for prayer and our clergy will continue to support those in need." 

The Catholic Archbishop of Liverpool, Malcolm McMahon, said he was holding all those affected by the tragedy in his thoughts and prayers and asked people to pray "for peace, healing, and justice". 

"For those who have been injured, for those who are parents, family, and friends of the injured, for all involved in the emergency services, we pray for God's blessing, God's peace, and God's presence today," he said. 

Christ Church Southport, which is one of the many churches opening their doors to the local community, said it was "heartbroken" over the attack.

"Our hearts and prayers go out to all those who have been affected. For those fighting in hospital, for those whose world has fallen apart, for those who are afraid, for those who first responded, for those who know someone that was there, for our town," the church said in a message posted to its Facebook page.