After four people died in an apparent terrorist attack in London yesterday, Pope Francis has voiced his sorrow and solidarity for the victims and their families, entrusting them and the nation to God's mercy.

"Deeply saddened to learn of the loss of life and of the injuries caused by the attack in central London, His Holiness Pope Francis expresses his prayerful solidarity with all those affected by this tragedy," a March 23 letter signed by Vatican Secretary of State Cardinal Pietro Parolin read.

The Pope commended the souls of those who died "to the loving mercy of Almighty God," and prayed for "divine strength and peace upon their grieving families," while assuring of his prayer for the entire nation.

Francis' letter comes the day after a deadly March 22 attack on London's Parliament took the lives of four people.

During the attack, a car apparently plowed into pedestrians on Westminster Bridge before crashing into the fence surrounding the Parliament building. The assailant then attempted to enter the Parliament building with a knife, stabbing one police officer before being shot by other officers on the grounds.

According to the Guardian, four people were killed, including the police officer who was stabbed and one man believed to be the assailant. About 20 others were reported injured, some severely.

Nearby government buildings were placed on lockdown while authorities worked to ensure the safety of the area. Scotland Yard said the attack is being treated "as a terrorist incident until we know otherwise."

The incident marks the first mass-casualty terrorist attack in Britain since the 2005 bomb attack on London that claimed the lives of 52 people when four bombers blew themselves up in the city's public transportation system.

March 22 also marks the one-year anniversary of the Brussels airport bombings that left more than 30 dead and 300 injured. Those bombings were declared the deadliest act of terrorism in Belgium's history.

The use of a vehicle as a weapon yesterday's London attack is reminiscent of the methods used last year by terrorists in Nice and Berlin.

Cardinal Vincent Nichols, Archbishop of Westminster, issued a March 23 statement to the priests and parishes of his diocese saying yesterday's attacks "have shocked us all."

"The kind of violence we have seen all too often in other places has again brought horror and killing to this city," he said, and urged pastors to lead their people in prayer, particularly for the victims and their families.

He offered special prayers for victim Aysha Frade, who was killed by the car on Westminster Bridge and whose two young children attend the diocese's St. Mary of the Angels Primary School.

He also offered special prayers for Frade's husband and a group of French students who were injured in the attack, as well as police officer Keith Palmer, the officer who died, and his family.

"Let our voice be one of prayer, of compassionate solidarity and of calm," the cardinal said.

"All who believe in God, Creator and Father of every person, will echo this voice, for faith in God is not a problem to be solved, but a strength and a foundation on which we depend."

(Story continues below)