Three people were killed and five others were wounded Sunday in Colorado in two different shootings, according to authorities. The shootings occurred at 12 hours and 70 miles apart, at a missionary school and a church. In the second incident the gunman was killed by a church security guard.

A police official said that the two incidents could be related, but no further information was given.

Colorado Gov. Bill Ritter said in a statement: "When innocent people are killed in a religious facility or place of worship, we must voice a collective sense of outrage,” San Francisco Chronicle quotes.

The first incident occurred in Arvada, a suburb of Denver, just minutes after midnight, when a man entered the Youth With a Mission dorm and asked for a place to stay for the night. When it was refused, the man, in his 20s, pulled out a gun and started shooting, killing two staff members and hurting other two. The gunman was wearing a dark jacket and a dark skull cap. He fled after the shooting and police searched for him with dogs.

Twelve hours later and 70 miles south, at an hour and a half of Arvada by car, in Colorado Springs, a gunman who was also wearing a dark jacket, shot a man in a parking lot of the New Life Church and injured other three people. He tried to get into the crowded church, but he was killed by a security guard, L. A. Times reports.

The gunman apparently used a smoke grenade, according to a witness.

Police in the both cities said that they are investigating whether the shootings were related.

Senior New Life pastor Brady Boyd said: “What happened today was a real tragedy. My heart is broken today for the people who lost their lives."

Late Sunday the dead gunman wasn’t identified by police.

After hearing of the incident in Arvada, New Life took measures and tightened up the security.

Colorado Springs Police Chief Richard Myers said regarding the security guard, that the "courageous security staffer . . . probably saved many lives."