MOSCOW (AP) — Tens of thousands of demonstrators have rallied throughout Russia to protest plans to substantially hike the age at which Russians can receive state retirement pensions.

A crowd estimated at more than 10,000 attended a protest in Moscow that was called by the Communist Party. A similarly large crowd gathered in Yekaterinburg to protest and demonstrations also were reported in large cities including Rostov-on-Don and Volgograd. No arrests were immediately reported.

Russia's lower house of parliament has given its first-reading approval to a measure that would gradually raise the pension ages from 60 to 65 for men and to 63 for women, up from 55.

Protesters called for a national referendum to be held on the issue before the parliament considers further readings of the bill after it resumes in September.