Gaza's Hamas rulers have imposed new entry restrictions requiring most foreigners to obtain a visa to enter the coastal territory, a move that could restrict the work of some international aid organizations.

Foreigners — mostly aid workers and pro-Palestinian activists — will now have to apply online or through a local sponsor a week in advance to obtain a monthlong visa, according to information posted on the Hamas Interior Ministry website late Sunday.

Information posted on the Hamas website said the new procedures would take effect on Tuesday.

A separate set of procedures for foreign journalists is still being completed, Hamas said, and U.N. workers would not be affected.

A Hamas official said the visa application will include a $7 registration fee, a requirement that could cause trouble for aid groups.

Most international aid organizations are prohibited from financial dealings with the Hamas government because the militant Islamic group is considered a terrorist organization by the U.S. and EU. Even a small visa fee would violate the restrictions.

"Basically as long as they keep insisting on us paying a registration fee when we go in, we can't go in," said an official with one prominent aid group that works in Gaza.

"If there's no money (involved), it's OK. We have no problem with registering. The problem is with paying," he said. He spoke on condition of anonymity because his organization, like others contacted by The Associated Press, declined to comment publicly on the sensitive issue.

Foreign aid workers in Gaza say they already struggle to obtain 6-month Israeli permits to enter through Israel's crossings.

Hamas' deputy interior minister, Kamel Abu Madi, said the new procedures were to ensure the safety of foreigners in Gaza.

"The aim of this mechanism is to organize the entry of foreigners into the Gaza Strip. Its aim is not to restrict them, but to serve their security," Abu Madi said.

Palestinian extremists killed 36-year-old Italian activist Vittorio Arrigoni in April. He had been living in Gaza since 2008 — apparently without the knowledge of Hamas officials, who said they need to keep closer tabs on foreigners to prevent such attacks.

Hamas officials already register the flow of foreigners at a series of checkpoints close to Gaza's borders with Israel and Egypt.

The move also comes in the context of Hamas' consolidation of control over Gaza, a territory it seized in 2007 after expelling forces loyal to Palestinian President Mahmoud Abbas. Neighboring Egypt and Israel have maintained a blockade on Gaza since the Hamas takeover, though Israel significantly eased restrictions on imports last year.

The militant Islamist group has long sought to limit the work of independent groups, including foreign charities.

Over the summer, the U.S. briefly suspended $100 million in American aid after Hamas officials demanded audits of local American nonprofit organizations and closed down at least one organization that refused to comply.

It was not clear how many aid groups would be affected by the visa order, but the impact could be significant. Aid groups run important farming, medical and psychological services in the impoverished territory.