SRINAGAR, India, Oct 28 (Reuters) - One person was killed and at least 20 people, including three Indian paramilitary soldiers, wounded when a suspected Islamist militant threw a grenade into a crowded market place in Kashmir on Saturday, an official said. The Indian Border Security Force (BSF) official said the attack which took place in Sopore town -- 50 km (30 miles) north of Srinagar, the summer capital of the Indian state of Jammu and Kashmir -- was aimed at a security patrol. "Three BSF personnel and 18 civilians were wounded in the explosion. Security forces have laid siege to the area," BSF spokesman Virender Manhas told Reuters. One of the wounded died in hospital. No militant group has claimed responsibility for the attack. A 17-year-old separatist revolt against New Delhi's rule has killed over 45,000 people in the strife-torn region claimed by both India and Pakistan. Authorities say violence has steadily decreased since the two countries, who have fought two wars over Kashmir, began a peace process in 2004. But people are still killed in daily shootouts and occasional grenade attacks.