* Nine dead including four foreigners in New Year attack
* Hotel seen as haven by foreigners and Afghan officials
* Taliban seek to disrupt April 5 election with 'full force' (Updates with latest on nationalities)
By Jessica Donati and Hamid Shalizi
KABUL, March 21 (Reuters) - A Taliban assault on the restaurant of a luxury hotel, considered one of the safest places in Kabul and frequented by foreigners and Afghan officials, has swelled a tide of violence sweeping Afghanistan two weeks before a presidential election.
Taliban gunmen smuggled tiny pistols past the Serena hotel's heavy security cordon and waited for the restaurant to fill up for an Afghan New Year dinner before emerging to shoot diners point-blank. Three children between two and five were found with bullets in their heads. Four of the nine dead were foreigners.
Hours later, a bomb attack in the southerly Kandahar province wounded the deputy governor and left his chief of staff in critical condition.
The Islamist Taliban movement has ordered its fighters to use "full force" to disrupt the vote and threatened to kill anyone who participates in what it calls a Western-backed sham.
This week alone, seven or eight suicide bombers killed at least 11 people in the eastern city of Jalalabad, while 18 were killed by a bomb in a marketplace in northern Afghanistan.
The April 5 vote is intended to mark the first democratic transfer of power in Afghanistan's history. It will be a pointer to prospects for stability as the NATO-led force that has been reinforcing security since the Taliban were driven from power in 2001 prepares to withdraw most of its troops this year.
With President Hamid Karzai constitutionally barred from seeking a third term, the front-runners include former finance minister Ashraf Ghani and two ex-foreign ministers, Zalmay Rassoul and Abdullah Abdullah.
The hotel attack started around 6 p.m. on Thursday when four attackers managed to get past the dozens of armed guards patrolling the perimeter as well as metal detectors and body searches, possibly concealing their guns in their socks.
Three hours later, they emerged to begin their rampage, killing four foreigners. The Interior Ministry gave conflicting accounts of their nationalities, but by late Friday said they included citizens of Canada and Paraguay. The U.S. embassy said a dual U.S.-Bangladeshi citizen was also killed.
The dead Afghans included popular journalist Sardar Ahmad of Agence France-Presse, his wife and two daughters.
Afghan special forces fought the gunmen for hours as terrified guests barricaded themselves in darkened rooms, listening to gunfire and the sound of running. Around 100 guests fled into a basement safe room, where they had to struggle with choking smoke from a fire in the kitchen above.
Although six people were killed in an attack on the hotel in 2008, its heavy security made it one of the few places in Kabul where foreign officials were still permitted to dine, after 21 people including three U.N. staff and a senior IMF official were killed in a Lebanese restaurant in January.
As shots rang out and diners dived under tables, one witness said Sardar had motioned for a foreign man, desperately seeking a hiding place, to take cover under a table with him and his children.
As two gunmen walked towards the group, Sardar spoke to them in a local language and the gunmen turned away and started shooting in a different direction until they ran out of bullets.
As they reloaded, the foreigner ran into the kitchen, where staff were guiding customers toward the safe room. But Sardar, his wife and two daughters were killed. Their young son was shot in the head, chest and leg, and was in critical condition.
All the Taliban gunmen were eventually shot dead, interior ministry spokesman Sediq Sediqqi said. The bodies were dragged through the hotel lobby, leaving long smears of blood, a witness said.
Friday's attack in Kandahar killed at least one person and wounded nine, leaving the governor's chief of staff fighting for his life in a military hospital, officials said.
"The doctor says that he is alive, he's in a coma, but will be okay," said Tawab Ghorzang, a spokesman for Afghanistan's governance agency. (Additional reporting by Katharine Houreld and Mirwais Harooni; Editing by Maria Golovnina, Miral Fahmy and Mark Trevelyan)