Israeli forces battled holdout Hamas fighters and pounded targets in the Gaza Strip on Sunday as Prime Minister Benjamin Netanyahu warned of a “long and difficult” war after the Palestinian militants launched a massive surprise attack.

Gun fights raged Sunday in towns and on highways as the Israeli army deployed tens of thousands of forces to secure southern desert regions near the coastal enclave, aiming to rescue Israeli hostages there and evacuate the entire region within 24 hours.

“We’ll reach each and every community until we kill every terrorist in Israel,” vowed military spokesman Daniel Hagari, a day after hundreds of Hamas fighters launched their shock offensive and surged into Israel using vehicles, boats and even motorised paragliders.

The worst fighting in decades has killed more than 200 Israelis, the army said, while Israeli media reported unconfirmed death tolls as high as 400 and 600, while on the Gaza side at least 313 were reported dead.

There was widespread shock and dismay in Israel after dozens of citizens were reported captured by Hamas gunmen and abducted into Gaza, with images circulating on social media of bloodied hostages, and distraught relatives pleading for the state to rescue them.

Yifat Zailer, 37, said she was horrified to see online video footage from inside Gaza that showed her female cousin and the woman’s children, aged nine months and three years.

“That’s the only confirmation we have,” she told AFP by phone, her voicing breaking, and adding there was no information on her cousin’s husband and her elderly parents. “After the army took control of the kibbutz, they weren’t at home,” she said.