WASHINGTON (Reuters) - In another sign of tighter security after last month's attacks on Washington and New York, authorities are barring most trucks from around the U.S. Capitol. The ban, which went into effect early Thursday, restricts commercial trucks capable of carrying more than 1.25 tons from streets bordering the Capitol complex, a U.S. Capitol police spokesman said. The prohibition also applies to other large vehicles, such as construction trucks and recreational vehicles, the spokesman said. Delivery trucks will have to undergo a security screening in which they will be examined, sealed and tracked electronically, Capitol Police spokesman Lt. Dan Nichols told local television stations. The decision to restrict traffic around the Capitol grounds followed weeks of debate among city leaders and federal authorities in the wake of the Sept. 11th attacks that killed more than 5,500 people.