The death toll from two days of militant bombings neared 140 - the deadliest spate in post-Taliban Afghanistan - after a suicide car bomb exploded in a crowded southern market, killing 38 Afghans, officials said. The marketplace bombing Monday, which targeted a Canadian military convoy, came one day after Afghanistan's deadliest insurgent attack since the Taliban's ouster in 2001. The toll from that blast - set off in a crowd watching a dog fight - rose to more than 100. The back-to-back bombings in Kandahar province could serve as a warning that insurgents have turned to collateral civilian deaths to further weaken the Kabul government. Though attacks occasionally have killed dozens, insurgents in Afghanistan have generally sought to avoid targeting civilians, unlike attacks that have scarred Baghdad in recent years. The attacks come amid warnings that Afghanistan this year could fall victim to even more violence than in 2007, when a record 6,500 people - mostly militants - were killed. The US, with a record high 28,000 troops in the country, is sending 3,200 more Marines in April.