The shooting on Friday at a movie theater in Aurora, a suburb of Denver, Colorado, that left 12 dead and 58 injured, sent the United States into mourning over the weekend and reignited calls for tougher gun control.

But there is no sign that US political leaders, lawmakers or the public are ready to take any steps toward tighter gun control.

US President Barack Obama offered his condolence to the victims on Friday morning. On Saturday, he ordered the US flag to fly half-staff for five days in mourning for the victims. In his radio weekly address on Saturday, Obama honored those killed in the tragedy, the people who knew and loved them and those still struggling to recover.

Republican presidential candidate Mitt Romney and House Speaker John Boehner joined Obama in consoling those traumatized by the shooting rampage.

But missing from their speeches was any mention of gun control - disappointing many who hoped the shooting would inspire more restrictions on firearms.

New York City Mayor Michael Bloomberg, a strong advocate for gun control, could not hide his anger. He strongly criticized national leaders just hours after the deadly shooting.

"Soothing words are nice, but maybe it's time the two people who want to be president of the United States stand up and tell us what they're going to do about it, because this is obviously a problem across the country. There are so many murders with guns every day - it's just got to stop," Bloomberg said in a Friday morning radio interview.

"And instead of these two people, President Obama and former governor Romney talking in broad terms about what they want to do to make the world a better place, ok, tell us how," he said.

"I don't think there's any other developed country in the world that has remotely the problem we have."

Bloomberg is co-chair of the Mayors Against Illegal Guns, a coalition of 600 mayors.

The Brady Campaign to Prevent Gun Violence, most vocal citizen lobby group against gun violence, set up by James Brady, former US president Ronald Reagan's press secretary who was wounded in a 1981 assassination attempt on the president, issued a statement criticizing Congress for doing nothing since the mid-1990s to keep guns out of the hands of dangerous people. It asked people to join their campaign to fight the National Rifle Association and the country's powerful gun lobby.

However, compared with the calls for gun control after deadly shootings in previous years, such as the Virginia Tech massacre in 2007, last years assassination attempt against Representative Gabrielle Giffords in Tuscon, Arizona, and the 1999 shooting at Columbine High School, only 20 miles from Aurora, the outcry this time was relatively muted.

Many analysts believe that the powerful gun lobby in Washington, DC, with the NRA as the major player, is the main reason why most politicians and lawmakers have remained mute on gun control following this latest tragedy. Some Democrats still recall how a 10-year assault-weapon ban passed in the Congress in 1994 was partly responsible for their loss in the House of Representatives several months later. When the assault weapon ban expired in 2004, congressional Democrats made no major efforts for an extension.

President Obama has not carried out his 2008 campaign promise to try to reinstate the assault-weapon ban. He has proposed nothing on gun control since taking office.

Even those who have tried to ban certain types of weapons have had little luck. New Jersey Senator Frank Lautenberg introduced a bill last year to ban the type of weapon used in the Giffords assassination attempt, but it was soon forgotten in Congress. He has since vowed to reintroduce the bill in the wake of Friday's shooting.

Chen Weihua reports in New York.