The London-based rights group Amnesty International is calling on Lebanese authorities to investigate allegations that security forces have used excessive force to disperse rallies protesting the government failure to deal with garbage piling in the streets.

The statement comes ahead of a major rally planned in Beirut on Saturday amid worries it would also descend into clashes.

Two rallies last weekend outside the government offices drew up to 20,000 people. Amnesty said security forces fired live rounds, used rubber bullets and hurled stones or beat protesters, leaving 59 people hospitalized.

In an interview with The Associated Press, Interior Minister Nohad Machnouk acknowledged there were "mistakes" that led to the excessive use of force and said an investigation was under way.