Afghanistan has postponed its parliamentary elections by four months until September, the country's election commission has confirmed.

Elections were to take place before May 22 under the constitution but a new date of September 18 has been set.

The commission cited a lack of funds and security concerns for the delay.

Last year's presidential election was marred by fraud, and Western nations have been pushing for reforms ahead of the parliamentary vote.

Fazil Ahmad Manawi, a senior election commissioner, told reporters in Kabul: "The Independent Election Commission, due to lack of budget, security and uncertainty and logistical challenges... has decided to conduct the [parliamentary] election on September 18, 2010."

The commission earlier said it needed about $50m from international donors to part fund the estimated $120m election budget.

United Nations funds are available to fund the elections but have been made contingent on reforms to the system.