An international climate activist group has claimed responsibility for deflating tires on 43 SUVs in Boston’s tony Beacon Hill neighborhood — and leaving behind preachy notes warning vehicle owners: “Your gas guzzler kills.” In a blog post, the group, which calls themselves the Tyre Extinguishers and claims to have 15,000 members worldwide, explained that Wednesday night’s stunt was their first foray into Boston, and that activists only targeted “large, luxury gas powered SUVs.” The eco-warriors noted that they spared hybrid, electric and handicapped-marked vehicles. “SUVs and 4x4s are a disaster for our health, our public safety and our climate. Bigger and bigger cars are dominating our towns and cities, and…