Image copyright Science Photo Library Image caption The Aedes aegypti mosquito is known to transmit Zika virus

The US Senate has failed to pass a funding bill to help fight the Zika virus for a third time.

Senate Democrats blocked the $1.1bn (£820m) bill after Republicans sought to stop funding for family planning group Planned Parenthood.

Lawmakers say they hope the issue will be resolved later this month as part of a bipartisan spending package.

The 52-46 Senate vote came as Florida health officials announced seven more locally transmitted cases of Zika.

Florida has now reported 56 locally transmitted cases of Zika, which is often spread by mosquitoes.

State officials have called on lawmakers to release funds to help fight the spread of the disease, which is linked to severe birth defects in pregnant women.

The Republican-backed Senate bill included a provision that would have prevented Planned Parenthood in Puerto Rico from receiving new funding to fight the spread of the virus, which can be sexually transmitted.

Puerto Rico has been one of the hardest hit regions with Zika in recent months.

Senate Minority Leader Harry Reid, a Democrat from Nevada, said Republicans were "more interested in attacking Planned Parenthood" than "protecting women and babies from this awful virus".

Senate Democrats blocked similar funding measures in June and July before Congress left for the summer recess.

What is Planned Parenthood?

A healthcare non-profit-making group with 59 affiliates and 700 clinics around the US

The largest single provider of abortion in the US

Its clinics provide many other healthcare services including cancer screening

Dates back to 1916 when social activist and nurse Margaret Sanger opened the first birth control and family planning centre in Brooklyn, New York

In the 1960s and 1970s, Planned Parenthood affiliates were at the fore of many court fights to make abortion legal

A controversial service

Before the vote, Republican Senate Majority Leader Mitch McConnell blamed his Democratic counterparts.

"It's hard to explain why, despite their own calls for funding, Democrats would block plans to keep women and babes safe from Zika," he said.

Republican House Speaker Paul Ryan has indicated that lawmakers will work to include funding for Zika in a budget deal or a continuing resolution that Congress must pass to avoid a government shutdown at the end of September.

The political gridlock comes after the Centers for Disease Control and Prevention announced that it had spent nearly all of the $22m (£16m) allocated to the agency in the fight against Zika.

As of late August, there were more than 2,700 cases in US states and more than 14,000 in US territories, most of which were reported in Puerto Rico.