The US special envoy to Afghanistan warned Monday that “distressingly high” levels of violence threaten to derail ongoing peace talks between the Afghan government and the Taliban. Zalmay Khalilzad’s comments come as renewed fighting for days has plagued Afghanistan’s southern Helmand province, a longtime Taliban stronghold. The Taliban this Friday agreed to halt its attacks on condition of the US stopping its airstrikes in the area. But then came a suicide car bombing Sunday that killed at least 13 people and wounded around 120 others in Afghanistan’s western Ghor province. Though no one claimed responsibility for the bombing, suspicion immediately fell on the Taliban, The Associated Press reported. “Violence has stalked Afghans for far too long. It has robbed far too many Afghans of their loved ones,” Khalilzad wrote on Twitter. “The tragedy in Ghor today is the most recent example.” The peace talks between the Taliban and Afghan government negotiators began in September, but after a ceremonious start they became bogged down. The current round of negotiations come after a deal in February between the US and the Taliban that seeks to end America’s longest war. According to AP, despite the challenges, the ongoing talks represent the most-serious effort yet at ending decades of war in Afghanistan that followed the 2001 US-led invasion that toppled its Taliban government, which then was hosting Qaeda leader Osama bin Laden who planned the Sept. 11 attacks.