Three women and a seven-year-old girl were on Saturday injured in a suspected drive-by shooting, police said, following a requiem mass for a mother and daughter in London.

Mourners ran screaming from the scene outside a Roman Catholic church in the capital as gunshots rang out.

"Initial enquiries suggest the shots were fired from a moving vehicle which was then driven away from the scene," London's Met Police said in a statement as they launched an urgent appeal for witnesses.

The priest who conducted the service, Father Jeremy Trood, told the PA news agency it had been a requiem mass for Sara Sanchez, 20, and her mother, who both died within a month of each other in November.

The younger woman had succumbed to leukaemia while her mother died after suffering a blood clot on arrival from Heathrow from Colombia, the MyLondon news website reported.

"I heard this almighty bang and I thought this was not normal, and the next minute everyone was screaming and shouting," a neighbour told PA.

The three women hurt in the incident, near to the busy Euston train station, were aged 41, 48, 54.

One of them had sustained potentially "life changing" injuries, the Met statement said, adding that the lives of the other two were not in danger.

The condition of the seven-year-old girl was not yet known, police added.

A witness told MyLondon the shots occurred as mourners who had attended the mass watched doves being released afterwards.

Police have launched an investigation