ATHENS (Reuters) - Greek police made limited use of teargas against pensioners protesting in central Athens on Monday over cutbacks to their benefits. About 1,500 pensioners attempted to march to Prime Minister Alexis Tsipras's office. Police blocked their path. Tensions flared when dozens of pensioners attempted to push over a police bus blocking their way a few hundred metres from Tsipras' office. The left-led government is expected to submit its budget for 2017 in parliament on Monday evening. (Reporting by Alkis Konstantinidis)