A judge on Thursday temporarily blocked the city from enforcing five gun-control ordinances pending a challenge from the National Rifle Association.

The NRA argues that state law prevents Pennsylvania municipalities from regulating guns, a view that even the city's crime-weary district attorney shares.

"The city has no basis to pass any of these gun-control ordinances and they know it," lawyer C. Scott Shields argued on the NRA's behalf.

City lawyers contend that Philadelphia can pass gun-control ordinances if the laws are outside the scope of state measures. As an example, lawyer Mark Zecca told the judge that one Pennsylvania county had banned guns at its courthouse.

Among other things, the five city ordinances passed April 10 ban the sale of assault weapons; require owners to report a lost or stolen gun within 24 hours; and limit firearms purchases to one a month.

They came in response to the city's one-a-day murder rate and its reputation for being a weapons source for criminals in New York and other states with strict gun laws.

The judge scheduled arguments for April 28. She said she would rule very quickly, although her decision is sure to be appealed by the losing side.

Mayor Michael Nutter, who declared a "crime emergency" shortly after taking office in January, quickly signed the City Council bills into law - despite still-pending litigation over earlier gun-control efforts.

US District Judge Joan A. Lenard Wednesday declared a second mistrial in a terrorism prosecution of six men charged with conspiring to bomb the Sears Tower in Chicago and the FBI headquarters in Miami after the jury was unable to reach a verdict after 13 days of deliberations. In December 2007 Lenard declared an initial mistrial when the jury was deadlocked after nine days of deliberations. A seventh man was acquitted in that proceeding.

The seven were indicted last year on charges of conspiring to provide material support to al Qaeda; conspiring to provide material support, training, and resources to terrorists; conspiring to maliciously damage and destroy by means of an explosive; and conspiring to levy war against the government of the United States. The indictment alleged that ringleader Narseal Batiste recruited the six other defendants to "organize and train for a mission to wage war against the United States government," and that they pledged an oath to al Qaeda in an attempt to secure financial and logistical backing. Lawyers for some of the men said that their clients were entrapped by an FBI informant posing as an al Qaeda operative. If the men had been convicted, they would have faced up to 70 years in prison.