Eyewitnesses on the street said armed police arrived at about 14:00 GMT and raided a house. They said they saw men being arrested and handcuffed. They were led by armed officers into a car. That street also remains cordoned off.
Chief Constable Serena Kennedy, of Merseyside Police, sought to reassure the public, saying events of this nature were very rare and that there would be an increased and visible police presence on the streets in the coming days.