BERLIN, Jan 18 (Reuters) - Germany must extend and tighten its lockdown measures to get down infection numbers in the pandemic more quickly, Finance Minister Olaf Scholz said on Monday. “I consider an extension and precise measures to increase the effectiveness of the (existing) measures necessary,” Scholz said, adding that stricter rules for working from home should be considered to reduce mobility and social contacts. German Chancellor Angela Merkel and the 16 state premiers are expected to discuss further curbs on Tuesday to slow the spread of new, more infectious variants of the coronavirus. (Reporting by Michael Nienaber; editing by Thomas Seythal)