Hamas authorities obstruct the work of Central Elections Commission (CEC) in the Gaza Strip, CEC chairman Hanna Nasser said Thursday.

Two weeks after Hamas allowed the CEC to operate in Gaza, the commission's staff are not yet allowed to start updating voter records, Nasser told Xinhua.

Hamas' government "asked us to linger in preparing for elections," Nasser explained, adding that this delay was unjustifiable."

In 2009, Hamas seized the CEC headquarters and drove out its staff. The offices were open again last month according to understandings reached between Hamas and Palestinian President Mahmoud Abbas' Fatah party in December 2011.

Abbas has recently issued a decree to form the CEC and nominate its members in accordance with a reconciliation agreement Egypt brokered between Hamas and Fatah in May 2011.

The agreement seeks and end to Palestinian political split, which was worsened when Hamas routed pro-Abbas forces and took over the Gaza Strip in 2007.

In Gaza, there are nearly 250,000 people unregistered in the voter records, which have come to a halt for four years, Nasser said. In the West Bank, where Fatah holds sway, the CEC is ready to hold polls and 85 percent of the records are updated.

The Palestinian factions initially agreed to hold elections in May 2012, but Nasser said the polls can not be held on schedule because the CEC needs at least 90 days to be ready.

On Sunday, Abbas and Hamas chief Khaled Mashaal agreed in Qatar that Abbas would form an interim government to prepare for elections.