The United Nations voiced alarm Tuesday as Israel launched a ground offensive into Lebanon as it targets Hezbollah militants, warning against a "large-scale ground invasion."

"With armed violence between Israel and Hezbollah boiling over, the consequences for civilians have already been terrible -- and we fear a large-scale ground invasion by Israel into Lebanon would only result in greater suffering," Liz Throssell, spokeswoman for the UN rights office, told reporters in Geneva.