At least two people have been killed and three others have been critically injured after a mass shooting in Baltimore overnight.

Police said 30 people were injured during the incident at a house party in the state of Maryland.

The Baltimore Police Department received numerous calls for a shooting just after 12.30am on Sunday morning, Acting Commissioner Richard Worley said.

He said officers arrived and located multiple victims suffering from gunshot wounds.

Ten people were taken to hospitals by police, while another 20 took themselves to hospital.

Detectives are working at an “extensive” crime scene to determine a motive, Mr Worley added.

Witnesses told local media hundreds of people had gathered for an event called “Brooklyn Day”.

Baltimore Mayor Brandon Scott said the “unspeakable” tragedy “highlights the impact and need to deal with the overproliferation of illegal guns on our streets”.

He said: “This morning all of Baltimore is grieving for the lives we lost here and our hearts are with all those as they are recovering as the result of this mass shooting.

“This investigation is ongoing and our homicide detectives will continue to work until they find out what happened here.

“What we do know this morning, this was a reckless, cowardly act that happened here and that has permanently altered many lives and cost two people their lives.

“And I want those who are responsible to hear me very clearly. We will not stop until we find you. And we will find you.

“Until then I hope with every single breath that you take that you think about the lives that you took and you think about the lives that you impacted here tonight.”