(Adds second blast, background) HERAT, Afghanistan, Dec 21 (Reuters) - Seven Afghans were killed and several wounded on Thursday in two separate bomb blasts, police said. A roadside bomb aimed at a senior Afghan police officer killed at least four civilians and wounded four, including the policeman, while another aimed at a convoy of foreign troops killed three policemen and wounded several, police said. The remote-controlled blast that killed four happened on a bridge on the main highway just south of the western city of Herat bordering Iran. No further details were immediately available. Herat is generally considered one of the safest parts of Afghanistan in the bloodiest year since the Taliban were ousted in 2001. No foreign troops were injured in the second blast which targeted their convoy in Khost province bordering Pakistan, police said. More than 4,000 people have been killed in fighting this year, a quarter of them civilians. As NATO seeks more troops and better flexibility to tackle a resurgent Taliban boosted by drugs money and safe havens in Pakistan, Germany said on Thursday it would probably approve an alliance request for help with aerial surveillance. "I believe there is a basic readiness to provide such aerial surveillance," deputy foreign minister Gernot Erler told German radio, adding parliament had yet to approve the NATO request. Berlin is expected to send six Tornado jets and about 250 more troops for the mission. Germany has 3,000 soldiers in Afghanistan, mostly stationed in Kabul and around the relatively stable north. It has resisted pressure from NATO allies, especially the United States and Britain, to redeploy some troops to the more volatile south, the Taliban's heartland and scene of most of this year's bloodshed.
