SCRANTON, Penn. (CBSNewYork/AP) — Hillary Clinton and Donald Trump have both cancelled campaign events scheduled Friday following a deadly attack on law enforcement in Dallas.

Clinton was expected to campaign alongside Vice President Joe Biden in Scranton, Pennsylvania on Friday. The Democratic presidential candidate is still expected to address the shootings later Friday at an appearance with the African Methodist Episcopal Convention in Philadelphia.

“I mourn for the officers shot while doing their sacred duty to protect peaceful protesters, for their families & all who serve them,” Clinton tweeted Friday.

MORE: CBS DFW | CBSN | Photos: Attack On Police In Dallas | Twitter Response

Clinton campaigned with President Barack Obama on Tuesday and her appearance with Biden in Pennsylvania, a general election battleground state, had been aimed at building party unity before the Democratic National Convention in Philadelphia.

Trump announced Friday a campaign event scheduled in Miami, Florida has also been cancelled.

Trump released a statement on his Facebook page Friday calling the incident an ‘attack on our country.’

“We must restore law and order. We must restore the confidence of our people to be safe and secure in their homes and on the street,” Trump said in the statement.

Trump continued, saying the nation has become “too divided,” and that racial tensions have “gotten worse, not better.”

“Our nation has become too divided. Too many Americans feel like they’ve lost hope. Crime is harming too many citizens. Racial tensions have gotten worse, not better. This isn’t the American Dream we all want for our children,” Trump said.

In an earlier tweet, Trump offered “Prayers and condolences to all of the families who are so thoroughly devastated by the horrors we are all watching take place in our country.”

Twelve officers were shot, five of them killed, after snipers opened fire on police at a rally in Dallas. The gunfire broke out Thursday night while hundreds of people were gathered to protest fatal police shootings this week in Baton Rouge, Louisiana, and suburban St. Paul, Minnesota.

Dallas Mayor Mike Rawlings said Friday morning that two civilians were also hurt.

Details on whether the events would be rescheduled was not immediately available.

(TM and © Copyright 2016 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2016 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)