ISTANBUL (Reuters) - Many Turks on Thursday welcomed their army's swift reprisal for deadly Syrian artillery fire into Turkey but their anger was tempered by fears of being dragged into full-blown intervention in a war that could blow back across their borders.
After shelling from Syria's civil war killed five people in a Turkish border town on Wednesday, parliament authorized the government to take military action in Syria if there was a further spillover of violence.
But while Turks voiced widespread support for a retaliatory round of Turkish shelling that killed five Syrian soldiers, fears of greater military involvement in Syria's civil war grew.
The Turkish slogan "savasa hayir" ("no to war") was the top trending item on Turkey's Twitter on Thursday morning.
Around 5,000 people took to the streets of Istanbul on Thursday evening in an anti-war protest which turned into a demonstration against Turkey's ruling AK Party.
"The AKP wants war, the people want peace," the crowds chanted as riot police looked on. "No to war, peace right now."
"We don't want war, we don't want young men to die," said Hatice Gokturk, a 62-year-old woman.
Earlier in the day, police fired tear gas to stop a small group of anti-war protesters from approaching the parliament in Ankara, chanting "We don't want war" and "the Syrian people are our brothers."
Opposition parties and civil society groups, expressing misgivings over the Turkish military response, called a further protest in Istanbul for later on Thursday.
An online survey by Hurriyet newspaper showed 60 percent opposition to the memorandum authorizing possible military deployments. Some fear Turkey is being pushed into the conflict by outside forces seeking to use Ankara to fulfill their agenda.
"We are carrying out other countries' business in the Middle East, it's not our war, and we should not be fighting the war of others," said 38-year-old waiter Mustafa Denizer.
"Turkey would drown in Syria if we try to go in there ourselves. We should avoid starting a war without international support."
Turkish artillery hit targets near Syria's Tel Abyad border town for a second day on Thursday in response to a mortar fired from Syria that killed a mother, her three children and a female relative on Wednesday.
"The Turkish people support such limited action, which has a positive impact psychologically, but they would not support a large-scale operation or war, because there is no legitimacy in Turkish eyes," said Nihat Ali Ozcan, security analyst at the TEPAV think tank in Ankara.
The government also seemed keen to allay fears of an escalation of the most serious cross-border incident of the 18-month-old uprising against Syrian President Bashar al-Assad, whose bloody crackdown on dissent wrecked relations with Turkey.
"Turkey has no interest in a war with Syria. But Turkey is capable of protecting its borders and will retaliate when necessary," Ibrahim Kalin, a senior adviser to Prime Minister Tayyip Erdogan, said on his Twitter account.
"Political, diplomatic initiatives will continue."
After parliament's approval of possible military action, Deputy Prime Minister Besir Atalay stressed Turkey's priority was to work in coordination with international institutions and that the authorization was not a "war memorandum".
Turkey has the second-largest army in NATO but its military activity in recent decades has been focused on fighting Kurdish militants at home and international peacekeeping operations.
Turkey's artillery strikes on Syrian military targets in the border area eased public pressure on the government that dated back to the shooting down of a Turkish military jet by Syrian air defenses in June.
At the time, Erdogan warned Syria to beware Turkey's wrath and changed the military's rules of engagement, authorizing the armed forces to react to any threat from the Syrian side of the border. Until Wednesday, however, Turkey's response had not gone beyond the occasional scrambling of warplanes.
"They were very slow in taking decisions and didn't respond. They were criticized domestically and this had a negative impact on people. Hence a response had to be made this time to overcome this psychological pressure," Ozcan said.
The memorandum in parliament would have the added effect of authorizing possible military action against Kurdistan Workers Party (PKK) militants believed to be active in northern Syria.
"This memorandum will also give the army authority to carry out operations against the PKK in Syrian territory," Ozcan said.
The PKK, mainly based in the mountains of northern Iraq, has waged a 28-year-old insurgency in which more than 40,000 people have been killed. Its proxy party in Syria has exploited the chaos to exert growing influence in the region bordering Turkey.
"We have to be very careful on our border with Syria. We must remain cool-headed and our reactions must be measured. The radical groups near the border may be trying to provoke Turkey into declaring war," said Mustafa Kemal Caniklioglu, 31, a restaurant manager in Istanbul.
Additional reporting by Ece Toksabay; Writing by Daren Butler; Editing by Mark Heinrich