HERAT, Afghanistan, Dec 3 (Reuters) - A suicide bomber killed four Afghans including two policemen and wounded six others in Afghanistan's western province of Nimroz on Monday, a provincial police official said. "The suicide bomber blew himself up near an Indian road construction company compound, killing two Afghan workers and two policemen in the Khash Rod district this afternoon," said provincial police chief Mohammad Dawood Askaryar. "No Indians were killed or wounded in the attack," he said, adding that six Afghan workers had been wounded. An official from the Indian company could not immediately be reached for comment. The hardline Islamist Taliban have killed at least 200 people in more than 140 suicide attacks this year in a campaign to defeat the government of President Hamid Karzai and eject some 50,000 foreign troops from Afghanistan. Over the past two years, Afghanistan has witnessed the worst insurgent violence since the Taliban government was ousted in 2001. More than 10,000 people including some 300 foreign soldiers have been killed in violence linked to militants. (Reporting by Sharafuddin Sharafyar, Writing by Hamid Shalizi, Editing by Caroline Drees)