Pakistani aircraft bombed militants in the South Waziristan region on the Afghan border on Tuesday as government forces prepare for a ground offensive against the militant hub, security officials said, according to Reuters. The government says most attacks in the country -- including four big ones over the past week that killed more than 100 people -- are plotted in South Waziristan, the main bastion of al Qaeda-linked Pakistani Taliban and their allies. "There's been a heavy bombardment. They targeted some militant hideouts as well as pro-Taliban tribal elders," said an intelligence agency official in the region. Two ethnic Pashtun tribal elders were said to have been killed, he said. Later, militants attacked a nearby military camp in the North Waziristan region, triggering a clash, residents and intelligence officials said.