With a 'heavy heart', US President George W Bush [Images] joined thousands across the United States in observing the fifth anniversary of the September 11 attacks. The day is being marked with all-faith prayers, wreath-laying ceremonies and silent marches in the areas hit by the terrorists.

The two-day commemoration ceremonies began with President Bush and first lady Laura Bush laying two wreaths of red, white and blue flowers in reflecting pools at the sites where the World Trade Centre's twin towers once stood.

The two also attended a prayer service at St Paul Chapel and visited a fire station overlooking the pit left by the fallen towers to show their appreciation for the work that the first responders did. They also remembered hundreds of them who died as the structures collapsed.

They walked down the long ramp hand-in-hand in silence to the site of the pools, which are about five stories below ground level. Police lined both sides of the path and bagpipes played a solemn tune.

After emerging from the firehouse, Bush said he is approaching the anniversary with a 'heavy heart' as he recalls those who lost their lives. He also called the day one for 'renewing resolve'.

"I vowed that I am never going to forget the lessons of that day," he said.

New York Governor George E Pataki, Mayor Michael R Bloomberg and the then mayor Rudolph W Giuliani also walked them down the ramp with them.

As many as 2,748 people were killed when terrorists crashed two airliners in the twin towers, which later collapsed in intense heat. Nineteen terrorists, who had hijacked the planes, too perished.

The wreath-laying was followed by an hour-long service at the Chapel. Several other functions were arranged across New York, New Jersey, Connecticut and other states to remember the victims.

Many commemoration events were lined up for the day like story readings, music and recitation of the names of those killed.

In New York city, where most of the deaths occurred and at other sites, the remembrances began early. Firefighters marched in streets to honour fallen comrades, bereaved family members knelt in chruch ceremonies and mourners paid homage to the souvenirs of their memories.

Walks and motorcyle rides were also organised in Washington to mark the occasion.

About 200 people were slated to read the names of victims, stopping only for moments of silence at the time when the two towers were hit and at the time they fell.

Even as Bush was attending ceremonies, Republicans and Democrats were feuding over the effectiveness of actions taken by the administration. The issue is being debated with an eye on the mid-term poll -- only six weeks away -- which could lead to Democrats capturing power in Congress.

The Republicans are trying to portray that the steps taken by the Bush administration have made the country safer and blame the previous Democratic administration of President Bill Clinton [Images] for ignoring the threat of terrorism.

Democrats, however, say that the Bush administration had been slipshod in the measures it took and the country is more unsafe than at other times.