By Tamsin Smith BBC reporter in Rome

Victims' friends, families and dignitaries turned out in force

People in the crowd wore their flags like scarves or capes.

They bowed their heads and made the sign of the cross as the coffins passed by, others shouted "grazie ragazzi" ("thanks boys").

Inside the Basilica, the caskets were draped in the national colours with a photograph of the deceased attached.

Sitting in the first few rows before the altar were the families of the victims and the Italian President, Carlo Ciampi.

Prime Minister Silvio Berlusconi and military and civilian leaders sat nearby as 4,000 mourners filed in behind them.

Open emotion

As the Mass started, Rome and much of Italy came to a brief standstill.

Shops closed, people left offices and schools to observe a minute's silence, others on the roads turned off car engines and lights and stopped to commemorate the troops killed in the southern Iraqi town of Nasiriya last week.

Some travelled across Italy to join in mourning

This is a national day of mourning but also of national pride.

Outside St Paul's, thousands of people crowded round giant screens and loudspeakers to follow the ceremony.

Many were from Rome, others had travelled through the night to be here.

"I'm from Milan, I drove all night to get here," said Massimo. "I wouldn't have missed it."

Spontaneous applause erupted and rippled through the crowd each time the live television camera was trained on the coffins.

As the name of each victim was read aloud, people wept audibly.

The broadcast also showed live footage from Nasiriya where the Italian troops there were holding there own brief commemoration and a moment of silence.

"This is really a beautiful ceremony and so it should be... no one deserves it more than these men, but it is so sad and painful to watch," Eliane said.

"I had to come here though. It is like these boys are everyone's children."

In his homily, Cardinal Camillo Ruini echoed the words of the Italian Government in the aftermath of the Nasiriya attack and said Italy would not be cowed by terrorism.

"We will not flee from them, rather we will confront them with all the courage, energy and determination that we are capable of," he said.

People in the crowd murmured their approval.

Remembrance

"This day makes us all feel numb," says Antonio, an army officer from Bari.

Italian soldiers said the deaths heightened the need to stay

"But I know one thing, and that is our boys must stay in Iraq... otherwise what's the point to lose our men for nothing?"

Andrea, a student from Rome agreed.

"I feel very emotional," he said, using the flag round his neck to wipe away tears.

"But this is the right way for us all to remember... I am upset but so proud of them and what they have done for us, for Italy."

At the end of the ceremony, a single bugle played.