More than 30 people were killed and scores of homes set alight in clashes in the past week between nomadic herdsmen and farmers in the central Nigerian state of Nasarawa, police said on Tuesday. Hundreds of people are killed every year in fighting between nomadic Fulani herdsmen and subsistence farmers over farmland and grazing rights in the mainly agrarian central region. Police said the latest clash erupted on Sunday when herdsmen attacked villages to avenge the killing on Dec. 6 of a Fulani nomad by farmers who said his cattle had destroyed crops. "Over 100 mostly mud houses have been burned and over 30 people on both sides, including one policeman, are believed to have been killed," Nasarawa state police commissioner Shehu Babalola told a foreign news agency. "There are claims that people were killed and thrown into the river."