Kidnappers escaped into Somalia with an elderly French hostage on Saturday after a battle with Kenyan coastguards and military forces. The gunmen had snatched the disabled woman from her beach home close to where a British man was killed and his wife abducted three weeks ago.

Officials had chased and surrounded a "suspicious vessel" reportedly heading towards neighbouring Somalia with six to 10 gunmen and the elderly hostage on board. Despite wounding several of the gang, officials said they had failed in their rescue mission.

"Now that it is dark it is next to impossible to continue to follow. The moment is lost," said Colonel John Steed, in charge of the UN's counter-piracy unit in Nairobi. "Now it reverts to normal kidnapping negotiations."

The kidnappers had stormed a seafront property near the Kenyan island of Lamu in the early hours of Saturday after arriving by speedboat.

Neighbours reported shots as the gang burst into the thatched house and rounded up staff before carrying off the woman. She was later named in reports as 66-year-old Marie Didieu, who has reduced mobility and uses a wheelchair.

John Lepapa, 39, described by local journalists as Didieu's partner, was quoted as saying the kidnappers ordered him and the house staff to lie face-down on the floor. "All they were saying was: 'Where is the foreigner, where is the foreigner?' " he said. "My girlfriend pleaded with them and told them to take whatever they wanted from the house, including the money, and to spare her life. But they would not listen."

One of the gunmen, he said, grabbed Didieu and carried her on his shoulders to a waiting boat. Kenyan police said they had not established if the assailants were Somali pirates, al-Shabaab Islamist extremists or a local gang.

Najib Balala, the tourism minister, said coastguard vessels surrounded the boat and there was a standoff between the Kenyan coastguards and the gunmen. Balala said the gang had fired into the air in an attempt to scare off the coastguard and circling aircraft.

Bernard Valero, a foreign affairs spokesman in Paris, said the foreign ministry was in "constant contact" with the Kenyan authorities, but did not confirm the identity of the French woman.

"Our ambassador and his team will do all they can to free our citizen, who is known to our embassy and very well liked locally," said Valero.

The kidnapped woman lives on the island of Manda, in the Lamu archipelago, near the Somali border. The area is popular with wealthy foreigners who own second homes there.

Jeremiah Kiptoon, who works on Manda, said he was woken around 3am by gunfire. "There were shots fired, dogs were barking and people were shouting," he said.

"I ran to the place where it was all happening, but by the time I arrived the woman was already gone. She has a small house close to the beach. Everyone was standing there frightened."

Somali pirates have frequently seized crew from merchant ships in the coastal waters off the Horn of Africa, but in recent years have targeted private yachts, snatching westerners and demanding – often successfully – huge ransoms.

In a similar attack on 11 September, David Tebbutt, a British publishing executive, was shot dead and his wife Judith taken hostage from their luxury holiday resort close to the Somali border.

The British couple Paul and Rachel Chandler were snatched from their yacht in 2010 and held for 13 months. They were released after a ransom was paid.

The Lamu archipelago is often included in package holidays to Kenya, together with game-viewing safaris in some of the country's national parks. France strongly advised travellers to avoid the region.