At least two policemen and seven suspected Tamil rebels were killed in Sri Lanka Thursday, news report showed here. Two policemen were killed when suspected rebels hurled a grenade at them in Vavuniya, 240 km north of capital Colombo, news agency Indo-Asian News Service reported.Later in the day, the Sri Lankan army opened fire at a group of suspected rebels inside two three-wheeler taxies in the Nelliady area, 390 km north of Colombo. The army claimed that the first three-wheeler carrying three rebels had hurled a grenade at the soldiers and they were fired on, killing all inside the vehicle. A second three-wheeler carrying four rebels had followed, and all of them were also shot dead, the agency reported.