Commuters suffered further delays on the Underground this morning, with a broken down train on the Victoria line adding to problems caused by the closure of the Northern Line.

The faulty train forced London Underground to suspend Victoria line services between Victoria and Warren Street stations, diverting thousands of passengers on to other lines.

The Tube network in central London is already struggling to cope with the closure of the Northern Line between Charing Cross and Golders Green, and between East Finchley and Euston.

This section of the line has been closed since Sunday, when a train derailed at Camden Town station on Sunday morning, injuring seven people.

It was the second safety incident on the Tube network in 24 hours, following the derailment of a Piccadilly line train near Barons Court station on Friday night, in which no-one was injured.

Transport for London has announced it will bring together London Underground bosses, union leaders, and officials from the Tube infrastructure companies, to discuss growing concerns over safety on the network.

London Underground managing director Tim O’Toole said the conference would examine safety issues on the Tube.

Mr O’Toole also said engineers may have to examine testing procedures, after admitting the crack in the track that caused the Barons Court derailment would have been difficult to spot without sophisticated testing.

The affected sections of the Northern line are to remain shut until next week at the earliest, it was announced yesterday.