Brno, Czech Republic  - Pope Benedict XVI began celebrating Sunday mass in Brno, the Czech Republic's second largest city, before a gathering of more than 120,000 people.

The papal mass marks the highlight of Benedict's three-day pastoral visit to the highly secular former Communist Eastern European country.

The pontiff was greeted by Czech President Vaclav Klaus on his arrival in Brno before being transported in his so-called popemobile to a specially-built podium on the tarmac of Turany Airport.

The crowd, many of them young people, cheered and waved Vatican flags, with some believers rushing towards the pontiff. Organizers said around 9,000 people from Slovakia, 1,000 from Poland and several hundred from Austria and Germany had travelled to Brno for the gathering. Some had arrived the previous night.

Benedict's sermon was expected to centre around message of hope. His first visit to the country comes as it marks two decades since the fall of Communist rule that was brought about by the Velvet Revolution in then Czechoslovakia and saw the return of religious freedom. Distrust of organized religion however remains deeply ingrained, and church-and-state relations remain strained in the Czech Republic.

"The pope can encourage the Catholics in the Czech Republic," said Rostislav Sery, a 19-year-old student who came from the village of Studlov, 150 kilometres east of Brno.

His friend, Jan Vanek, an 18-year-old student, said: "It is difficult for young people in the Czech Republic to be Catholic."

The 82-year-old pontiff, who arrived in the country Saturday, is set to end his tour Monday with a tribute to Czech patron saint, Wenceslas, in Stara Boleslav outside Prague. dpa