Mumbai, July 10 - Security was beefed up at several key stations here Friday following intelligence alerts of a probable attack on the eve of the third anniversary of the 7/11 terror blasts.

'Security measures were intensified Thursday at Churchgate, the Western Railway headquarters and Andheri,' a railway official told IANS on condition of anonymity.

Traffic on certain approach routes to Andheri and Churchgate was diverted and random checks, machine checks, frisking and checking of vehicles were being carried out by personnel of the Mumbai Police, Railway Protection Force (RPF) and the Government Railway Police (GRP).

The network of suburban trains, encompassing services by the Central Railway, Western Railway and Harbour Line, is the lifeline of Mumbai and is used by over seven million commuters daily.