Police have stepped in to help passengers off two trains stranded by electricity supply problems.

One train has stopped near Emanuel School in Battersea Rise. The other was evacuated in the Clapham Common area earlier this morning, British Transport Police (BTP) said.

Wandsworth police tweeted: "We're on scene at the tracks by Emmanuel School to assist @BTP with helping ppl from a stranded train. Road closures in place in the area."

Station Manager Nic Myatt, of London Fire Brigade, said: "We used a short extension ladder to assist Network Rail and British Transport police in detraining approximately 1,000 people along the tracks and on to a rail replacement bus service."

Fire crews left the area shortly before midday.

National Rail said that electrical supply problems were causing delays of up to 90 minutes between Balham and London Victora, and Watford Junction.

Gatwick Express services are not running, and disruption is expected until midday.