New Delhi, March 9 (IANS) Prime Minister Manmohan Singh Tuesday called Rajya Sabha chairman Hamid Ansari to express regret at the 'unruly behaviour' of some MPs who had torn the women's reservation bill and hurled the pieces at the chair the day before.

'The prime minister called up the Rajya Sabha chairman and was unhappy at the unruly behaviour witnessed in the upper house,' said an official in the Prime Minister's Office.

The Rajya Sabha was adjourned six times Monday. When the bill, which promises to reserve 33 percent of legislative seats for women was presented in the house, some MPs tore it up and threw the pieces at the vice president.

On Tuesday, a furious Ansari suspended seven MPs for the remaining part of the session when the disruptions continued.