A top U.S. Democrat said Sunday she would introduce a bill banning assault weapons as soon as the new Congress convenes in January in the wake of the deadly school shooting in Connecticut.

"I'm going to introduce in the Senate, and the same bill will be introduced in the House, a bill to ban assault weapons," Senator Dianne Feinstein of California told NBC's "Meet the Press" program.

Pope Benedict XVI on Sunday prayed for families of the victims in the Newtown school massacre in the United States during his traditional weekly address to pilgrims in St. Peter's Square.

"I was deeply saddened by Friday's senseless violence in Newtown, Connecticut. I assure the families of the victims, especially those who lost a child, of my closeness in prayer," the pope told thousands of pilgrims.

The gunman in the Connecticut school massacre that left 20 small children dead blasted his way through a locked glass door, climbed through and proceeded with his killing spree, the state governor said Sunday.

"He shot his way into the school. The school was locked. He used a weapon to open up the glass, and then walked in," Governor Dan Malloy said on the ABC program "This Week."

On leafy Yogananda Street, home to Nancy Lanza and her son Adam Lanza, the accused U.S. school gunman, former school mates Saturday remembered him as an intelligent but strange young man.

"He was a weird kid as a child, but he was just quiet. We never knew his real personality. He was just himself," said Megan, aged 20, who went to primary school with the presumed shooter, and declined to give her last name.

Globe-trotting U.S. Secretary of State Hillary Clinton hit her head and suffered a concussion while battling a nasty stomach bug, officials said Saturday, forcing her to stay home for a second week.

"While suffering from a stomach virus, Secretary Clinton became dehydrated and fainted, sustaining a concussion," Clinton's top aide Philippe Reines said in a statement.

Iran was quick on Saturday to express condolences after the "tragic" shooting rampage that left 26 people dead, including 20 small children, at an elementary school in the United States.

Foreign ministry spokesman Ramin Mehmanparast condemned the "tragic incident" and expressed sympathy with the families of the victims, the state broadcaster's website IRIB reported.

Russia on Friday condemned U.S. sanctions against officials implicated in the death of anti-corruption lawyer Sergei Magnitsky as "dangerous" meddling and hit back with moves for a bill of its own blacklisting American citizens.

The bill, which grants normal trade relations with Russia but also includes a blacklist of alleged human rights abusers, had angered Russian President Vladimir Putin and was signed into law Friday by President Barack Obama.

U.S. Deputy Secretary of State William Burns called on Friday for long-term solutions to fight terrorism, a phenomenon he said posed "serious threats" in the Sahel and the Horn of Africa.

"Our goal now is to put into place long-term solutions," Burns said at a meeting of the Global Counterterrorism Forum in Abu Dhabi.

Will she, won't she, will she, won't she, will she join the dance? To borrow from "Alice's Adventures in Wonderland," that's the question on everyone's lips about Hillary Clinton and the 2016 White House race.

And just like Alice, who followed the White Rabbit down the hole into a strange and topsy-turvy universe, nothing is ever quite what it seems in Clintonland or the ever-shifting world of U.S. politics.

A strong 6.4-magnitude earthquake struck off the coast of California early Friday immediately followed by a 6.1-magnitude temblor, according to the U.S. Geological Survey.

There were no immediate reports of damage or casualties from the earthquakes, which took place 262 kilometers (163 miles) and 93 kilometers (58 miles) off the coast, respectively, according to seismologists.