The Pope has celebrated¹ the traditional Christmas Mass, despite being knocked down by a woman at the start of the service in St Peter's Basilica.

罗马教皇在圣彼得大教堂举行圣诞弥撒，尽管开始的时候被一位妇女撞倒，但是他仍然继续进行庆祝活动。

A woman jumped the barriers and knocked the Pope down

The woman - who is said to be mentally unstable² - jumped the security barriers as Benedict XVI entered the basilica长方形基督教堂, causing the pontiff to fall.

The Pope appeared to be unhurt and recovered to lead the Mass.

The midnight service started two hours early because officials do not want the 82-year-old pontiff主教，教皇 to get tired.

Thousands of pilgrims also gathered in Bethlehem to celebrate Christmas Mass圣诞弥撒.

Latin Patriarch Foud Twal, the most senior Roman Catholic cleric牧师，传教士 in the Holy Land, said the region's aspiration³渴望，报复 of peace remained out of reach.

"The wish that we most want, we most hope for, is not coming," he said after passing into Bethlehem in a traditional holiday procession列队行进 from nearby Jerusalem.

"We want peace."

Woman arrested

The security incident involving the woman at St Peter's Basilica lasted only a few seconds.

The woman - who was reportedly wearing a red jumper工作服，妇女穿的套头外衣 - tried to jump the barrier and the Pope was thrown off摆脱，抛弃 balance and fell, prompting shocked gasps⁴ among the crowd.

Security officials rushed down the main aisle通道，走廊 to detain the woman.

The Pope had to be helped up by the master of ceremonies at his side, the BBC's David Willey in Rome says.

However, he quickly recovered his poise⁶姿势，平衡 and passed into the basilica preceded by senior Vatican cardinals红衣主教, our correspondent says.

Benedict then delivered the Christmas homily说教，训诫 in a firm voice. The theme was selfishness which, he said, "makes us prisoners of our interests and our desires".

The woman who pushed the Pope also knocked down Cardinal⁷ Roger Etchegaray, who was taken to hospital for a check-up, Vatican spokesman Ciro Bedettini said.

The woman - whose name was not immediately known - was later arrested by police.

During last year's Mass, a woman also jumped the barriers and got close to the Pope but was quickly restrained抑制，束缚 by security officials.

It was not immediately known if it was the same woman who pushed Benedict on Thursday.

The Vatican said earlier that the decision to move the midnight Mass to 2200 (2100 GMT) was "to make Christmas a little less tiring for the Pope, who has many engagements".

The pontiff earlier appeared briefly⁹ at nightfall at the window of his studio to light a candle in a sign of peace.