Suspected smugglers opened fire from Syria and shot dead a Turkish soldier on Thursday, the second cross-border firefight to have killed a member of the Turkish security forces in as many weeks, a senior government official said.
The soldier was killed in the Reyhanli district of Turkey's Hatay province, across the border from a part of Syria notionally controlled by Western-backed Free Syrian Army rebels, the official said.
One soldier was killed and another is still missing after a cross-border shooting with Islamic State fighters last week near the Turkish town of Kilis, further east. Turkey's Hurriyet newspaper said on Saturday that the missing soldier had been seen in a hospital run by Islamic State.
But Thursday's shooting appeared not to be related to the radical Sunni militant group.
"We don't think it's related to Islamic State because there is Free Syria Army across from Reyhanli. We've observed that the measures we took against smuggling have been effective, so it's highly likely that the soldier was killed from fire opened by smugglers," the official said.
Turkey has tightened border security in recent months and stepped up military action against Islamic State in July, opening its air bases to US-led coalition war planes and launching air strikes.
If confirmed, the capture of the soldier by Islamic State during last week's shooting near Kilis could become a major challenge for the government in Ankara, particularly as it gears up for a crucial Nov. 1 snap election.
Late last month, Islamic State released a video accusing President Tayyip Erdogan of "treachery", and urged Turks to rise up against him.