Voters in the oil-rich ex-Soviet republic of Kazakhstan cast ballots Sunday in general elections aimed at adding a second party to parliament.

Local and Western news media reports said voter turnout easily exceeded the 70 percent mark as polls closed Sunday evening.

To date, all seats in the Kazakh parliament has been occupied by President Nursultan Nazarbayev's Nur Otan party, which was certain to win Sunday's election by a landslide. But under new law, the second-place party is guaranteed a presence in parliament, whether or not it clears the previously required 7 percent entry threshold.

Elections monitors from the Organization for Security and Cooperation in Europe were set to issue a preliminary report Monday on the conduct of the polls.

Kazakhstan has become an increasingly important source of oil and natural gas, and provides a key northern supply route for U.S.-led military operations in Afghanistan.

The 71-year-old President Nazarbayev remains overwhelmingly popular throughout most of the mainly Muslim country. He has been Kazakhstan's only president since it gained independence in 1991.

Sunday's elections took place a month after a long-term protest in the town Zhanaozen by laid-off oil workers degenerated into clashes with police. At least 15 people were killed in the violence.

Speaking Sunday from Zhanaozen, OSCE poll monitor John Anderson said there were no signs of voting irregularities in the town.

“As I have seen the organization and the administration by the electoral commission is showing an orderly process. I note that apparently the turnout is not as it has been in the past, this is understandable and I hope that everyone comes and exercises their right to vote and it was certainly from what I've seen the right decision to allow for the voting process to continue here in this town today.”

In 2011, Monitors reported numerous instances of ballot box stuffing, voter intimidation and lack of transparency in presidential elections.