QUITO, Ecuador — A knife attack in Ecuador that killed two government supporters was perpetrated by a man under the influence of drugs and alcohol and was not politically motivated, President Rafael Correa said on Tuesday.

The man killed two Correa supporters and injured five more at a campaign rally on Monday, about two weeks before a presidential election that the leftist leader is expected to win comfortably.

"There is no indication that this attack may have been politically motivated. It was a person who was temporarily insane and stabbed the people that he found in his way," Correa said at a press conference in Quito. "This person was under the influence of drugs and alcohol."

A 40-year-old man with a criminal record who had spent time at a drug rehab center was detained shortly after the attack and is in police custody.

Correa said that five people were injured, one more than the number previously given by authorities.

Such incidents are exceedingly rare in Ecuadorean political campaigns despite historically volatile politics in which presidents have been toppled during street protests.

It was the first significant act of violence in a presidential race that officially started on Jan. 4.

In a chilling video broadcast on local TV networks, a man could be seen breaking through a rally of a few hundred Correa sympathizers and attacking them with a large knife. Dozens ran for their lives while some men tried to stop the attacker.

Correa said police at the event were caught off guard. He said the attack lasted less than 20 seconds.

The incident occurred ahead of a campaign rally in Quininde, a town in the western Esmeraldas province. The event was canceled following the attack and Correa suspended his campaign on Tuesday in solidarity with the victims.

Correa, an ally of socialist Venezuelan leader Hugo Chavez, is expected to win the Feb. 17 vote. Polls give him between 50 percent and 60 percent of votes, at least 30 percentage points ahead of his nearest rival, Guillermo Lasso, a former banker.

The president is very popular in urban shanty towns and rural areas, where millions have seen their livelihoods improved thanks to record spending in roads, hospitals and schools.