Ashkenazic Chief Rabbi of Israel David Lau said on Thursday "My instruction is that synagogues should not be closed, but the obligation is to behave in accordance with the requirements and guidelines issued by the Health Ministry [regarding the coronavirus]. In practical terms, until another instruction is issued, it is possible and important to pray in the synagogues," but those coming to pray must be divided into minyanim (prayer quorums) so that each minyan has only ten men.
Rabbi Lau added, "It is forbidden for people who are old or at risk to go to the synagogue and they should pray in their home while the public is praying [in the synagogue]. He said that if the Health Ministry conditions are not met, people should leave the syngagogue building.