Five people have been killed in a shootout and grenade attack within sight of the Kremlin, Itar-Tass said Monday. Police and witnesses said the attack began at about 5 P. M. Friday when several men leaped from a BMW and began firing into the ground floor office of a three-story building under repair at 15 Ulitsa Dmitrova. The gunmen's getaway was foiled, however, when a grenade exploded beneath their car, according to an account in the newspaper Commersant Daily. Three people were shot dead inside the office, belonging to a commercial company, while the fourth, a driver, was killed outside. All four were visitors to the company, Itar-Tass said. Police searching the site of the crime later found the body of a man who had been strangled, the news agency said. Police declined to identify the victims, speculate about a motive, or say whether any arrests had been made. Itar-Tass, however, said the deaths were probably linked to a debt of $100, 000 that the company had run up.