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By Mirwais Harooni and Hamid Shalizi
KABUL, June 22 (Reuters) - Afghan Taliban gunmen, some armed with rocket-propelled grenades and heavy machine guns, have attacked a hotel in Kabul's popular Qargha Lake recreation area, triggering a gunbattle, Afghan police said on Friday.
"Insurgents armed with RPG rockets, and heavy and light weapons are inside the Spozhmai Hotel and fighting with security forces. We don't know their numbers and if there have been casualties," said Mohammad Zahir, head of the Criminal Investigation Department of the Kabul police.
The Afghan Taliban claimed responsibility for the attack, saying wealthy Afghans and foreigners used the hotel, about 10 km (6 miles) from the Afghan capital's centre, to have "wild parties" in the lead-up to the Friday religious day holiday.
The lake is one of Kabul's few alternatives for weekend getaways. Restaurants and hotels that dot the lakefront are popular with Afghan government officials and businessmen, particularly on Thursday nights.
Violence across Afghanistan has surged in recent days, with three U.S. soldiers and more than a dozen civilians killed in successive attacks, mostly in the country's east where NATO-led forces have focused efforts during the summer fighting months.
President Hamid Karzai told a special session of parliament on Thursday that attacks by insurgents against Afghan police and soldiers were increasing as most foreign combat troops prepare to leave Afghanistan by the end of 2014.
Police were reluctant to storm the hotel because an unknown number of families were trapped inside, said a police source who could not be identified because he was not authorised to speak to journalists.
"We are afraid if we take serious action and fight them it will result in losing lives among civilian families," he said.
The attack had been underway for about four hours as dawn broke over Kabul.
Afghan insurgents attacked Kabul's heavily protected diplomatic and government district on April 15 in an assault eventually quelled by Afghan special forces, guided by Western mentors. (Writing by Rob Taylor; Editing by Paul Tait)