* Two killed in unrest which erupted on Thursday
* Violence so far contained in one Istanbul neighbourhood
* Anniversary of last year's anti-govt protests approaching (Adds details of second death, background)
By Ece Toksabay
ISTANBUL, May 23 (Reuters) - A second person died on Friday after clashes between Turkish police and protesters in a working-class district of Istanbul, stirring fears of further unrest as the anniversary of last year's anti-government demonstrations approaches.
Istanbul Governor Huseyin Avni Mutlu called for calm "for the security of the nation" after protesters throwing petrol bombs and stones clashed with riot police in the city's Okmeydani district on Thursday.
The violence in the neighbourhood, which has seen periodic unrest since the 1990s, comes almost a year after protests in Istanbul triggered a summer of nationwide demonstrations which challenged Prime Minister Tayyip Erdogan's decade-old rule.
Erdogan, who is expected to stand in a presidential election in August, has had a difficult twelve months, with last year's protests, a corruption scandal dogging his inner circle, and a mine disaster last week drawing renewed criticism of his leadership.
His government will be anxious to avoid a repeat of last summer's scenes, when a police crackdown on a demonstration against the redevelopment of an Istanbul park at the end of May triggered weeks of street protests in major cities.
The Okmeydani unrest has so far showed little sign of spreading to other parts of Istanbul, including its central Taksim Square, an epicentre of last year's troubles which has been guarded by a small contingent of riot police ever since.
"Everyone must help bring the situation back to normal. We need calm, we need to act in a calm manner for the security of Istanbul and of the nation," Mutlu told reporters, warning residents to be on their guard against "provocations".
A bystander, Ugur Kurt, who was attending a relative's funeral, was shot in the head apparently by a stray bullet as the violence flared on Thursday. His death in hospital overnight triggered renewed clashes in which a second person, as yet unidentified, was killed by a home-made grenade, Mutlu said.
"Some people are engaged in an effort to escalate these events ... I am calling on every citizen to be wary," he said.
Nine people, including two protesters, a police chief and six of his officers, were injured when the grenade was thrown, the city's police department said.
Kurt's funeral was due to be held in Okmeydani on Friday and could become another rallying point for protests.
Okmeydani is home to a community of Alevis, a religious minority in mainly Sunni Muslim Turkey who espouse a liberal version of Islam and have often been at odds with Erdogan's socially conservative, Islamist-rooted government.
It has seen frequent left-wing protests in the past.
Thursday's disturbances began when a group of some 10 to 15 people began chanting slogans about a youth, Berkin Elvan, who died in March after clashes with police, and about the mine disaster last week in which 301 people died.
Elvan, 15, died after nine months in a coma from a head wound sustained during an anti-government protest in Okmeydani. Thousands clashed with police in Istanbul when he was buried.
Deputy Prime Minister Bulent Arinc told parliament that prosecutors would investigate Kurt's death. (Writing by Nick Tattersall; Editing by Alison Williams)