ATHENS (REUTERS) - Greek police on Monday (Oct 3) fired teargas to control a demonstration of pensioners protesting cutbacks to their benefits as part of an austerity drive requested by international lenders.

About 1,500 pensioners attempted to march to Prime Minister Alexis Tsipras' office, but were blocked by riot police.

Tensions flared when dozens of pensioners attempted to push over a police bus blocking their way a few hundred meters from Tsipras' office.

The angry protesters pushed against the police cordon of raised shields, throwing water and other objects at riot police, and shouting "Shame!" as they attempted to tip over the police bus. Police responded with teargas.

The left-led government is expected to submit its budget for 2017 in parliament on Monday evening.

Greece has been reeling from the impact of painful austerity for the past seven years, required by creditors as a remedy for years of financial mismanagement which culminated in three international bailouts.

Pensioners have been particularly hit, with many benefits pared as taxes have spiked.