The Turkish government has made the unusual move of confirming that its special forces entered Syria on Saturday, on what it called a "reconnaissance mission".

Al Jazeera's Stefanie Dekker, reporting from Gaziantep near the Turkish-Syrian border, said it was highly unusual for the Turkish government to announce a special forces operation conducted outside the country's borders.

"Perhaps they were trying to give a message by announcing something so secretive," she said.

She said the operation was probably an attempt to stop the almost daily attacks on Kilis, a Turkish border province which has been hit by rockets from areas in Syria controlled by the Islamic State of Iraq and the Levant group (ISIL, also known as ISIS).

Separately, the Turkish military said it killed up to 55 ISIL fighters in the Baragitah area of northern Syria on Saturday.

According to Turkish media reports, three vehicles and three rocket launchers that belonged to ISIL were also destroyed.

READ MORE: Rockets from Syria kill four Syrians in Turkey's Kilis

More than 20 people have been killed and scores more wounded in attacks blamed on ISIL since the beginning of this year. Over the past two weeks rockets have been falling on the city every day.

"There is a lot of fear, frustration and concern in Kilis," Dekker said. "I think the Turkish government is sending a message to the residents of Kilis with this operation. They are saying that they are actually trying to do something to make it stop."

'We are dying'

One day before the Turkish special forces operation, several prominent Kilis-based NGOs published an open letter in national newspapers, asking the Turkish state to take action.

"Rockets are falling on our houses, shells are raining on us. We are being killed on the streets, we are being killed in our houses," the letter said.

"We are Turkish citizens, we want to feel safe. Please hear our call, please respond. We know you did not forget us. We know you are trying to help," the letter continued. "But please be quick, we are dying. Kilis is under attack. Homeland is under attack."

Kilis lies just across the border from an area controlled by ISIL.

It is the only province in Turkey where refugees from the war in Syria - about 110,000 - now outnumber Turkish locals.

"People who have been displaced internally in Syria over the course of this war are now in Turkey thinking that they can be safe," Dekker said, "Yet rockets are falling on their homes."

Turkey is currently facing several security threats. As part of a US-led coalition, it is fighting ISIL in neighbouring Syria and Iraq as well as Kurdish fighters in its own southeast and northern Iraq.