Spurred by the railway bombings in Madrid last month, the Senate Commerce Committee on Thursday unanimously approved spending more than $1 billion to protect railroads and mass transit systems from terrorist attacks.

The bill requires the Homeland Security Department (search) to develop a plan within 180 days to improve rail security throughout the country. It calls for tightening security at railroad stations and tunnels and for railcars that carry hazardous materials.

Commerce Committee Chairman John McCain (search), R-Ariz., said the terrorist strike in Madrid showed "we need to pass this legislation as soon as possible."

The committee passed a similar bill in the month after the Sept. 11, 2001, terrorist attacks, but it never went any further.

Last week, the FBI and the Homeland Security Department warned that terrorists might strike trains and buses in major U.S. cities using bombs concealed in bags or luggage.

Since the bombings in Spain that left 191 people dead, lawmakers have criticized Homeland Security for focusing too heavily on protecting commercial air travel at the expense of other kinds of transportation.

The government has spent $12 billion on aviation security since the attacks on the Pentagon and the World Trade Center (search). Railroads and transit agencies were authorized to receive $65 million in security grants in 2003 and $50 million in 2004.

The committee approved a separate measure requiring the Homeland Security Department to develop a port security plan. Though the bill would have awarded $400 million a year in grants to protect the maritime industry, a proposal to impose a user fee to pay for them failed.

Also Thursday, the Bush administration backed a proposal by Sen. Jeff Sessions, R-Ala., that would beef up federal penalties for rail attacks and end some decades-old discrepancies between punishments for targeting freight and passenger trains.

The proposal, which representatives of the Justice and Transportation Departments (search) endorsed at a Senate Judiciary Committee hearing, also would make it a federal crime to release biological or hazardous materials on any mass transportation provider, including trains. Should anyone be killed in such an attack, the death penalty would apply.