Police detained the suspects during the search of a vehicle of people who entered Turkey illegally.

On Monday, one student was killed and a number of people injured after shells were 'most probably fired from Syria' on a school compound in the border province Kilis, according to Mayorship.

Intensified operations over attack

Previously, Turkish police detained 10 people suspected of links with Daesh in the central province of Konya.

Days before the operation in Konya, 60 other Daesh-linked suspects were captured in operations in several other Turkish cities.

The operations against Daesh have intensified as a part of heightened security measures after the bloody terror attack in Istanbul.

The suicide bombing targeted Istanbul's Sultanahmet Square, a major tourist attraction, and left 10 people dead and 15 others wounded on January 12.

Security sources said Turkish military opened cross border fire to according the rules of engagement as early fire from Daesh-held areas in Syrian border villages killed a student and injured several more in Southeastern Turkish province of Kilis.

The shell blast reportedly took place at 9:30 am at Eyüp Gökçe Secondary School in central Kilis.

Rescue teams and ambulances were sent to the scene amid reports of wounded students.

The Kilis Mayorship said that the shells were most probably fired from Syria.

School explosion leaves casualties in southeastern Turkey

The sources said the number of detainees increased by 61 percent (564 persons) in the second half of the year, compared to 349 persons during the first six months of this year.

Only 108 terror suspects have been detained in land and air operations between November and December, according to the security authority.

Regarding the nationality of the total detainees, China leads the list with 324, while Russia follows it with 99 Russian citizens.

Authorities detained 478 people while trying to enter Turkey and another 435 were detained crossing the border into Syria.

Foreigners who tried to enter Syria told investigators that they intended to enter Syria illegally to find their relatives. On the other hand, some of those who tried to enter Turkey claimed to be fleeing from Daesh oppression, while some others admitted they took arms training in Daesh camps and were plotting to attack inside Turkey.

Security forces also seized weapons and other materials which could be used for terrorist attacks.

In recent years, Ankara has adopted a host of security measures focusing on border regions to prevent entry of foreign fighters in transit to join terrorist organizations in Syria.

The measures indicate a multi-pronged approach, including the establishment of Risk Analysis Units at custom gates and transportation centers. The units, which are currently in use, had bolstered capacity for security checks on incomers.

Security forces also keep a tight rein on those who entered legally

At the border, the Turkish Armed Forces are taking extra measures to prevent foreigners from joining clashes in Syria.

Troops have dug 365 kilometer long ditches, and a 270 kilometer stretch on the border has been illuminated to make patrolling more effective. Additionally, 1,280 kilometers of patrol roads have been improved.

Turkey has also fortified its border region by deploying personnel and vehicles on the Syrian border.

The group, including three children, were held by border troops on Friday in Elbeyli town of Kilis as they were attempting to cross illegally into Turkey from Syria, Turkish General Staff said in a statement on its official website.

It added that they were caught with an AK-47 rifle, rounds and four grenades.

Turkish General Staff said in a statement on its official website that the suspects were held by border troops Sunday as they were attempting to cross illegally into Syria from Elbeyli town,

Turkey captured more than 2,627 members of ISIL, including 837 foreign nationals, over the past three years, often as they try to enter Syria by crossing the Turkish border.

The operations were based on an intelligence report conveyed to Kilis military police command, warning that seven foreign nationals and two ISIL members would attempt to cross into Syria on their way to Raqqa, the ISIL stronghold.

The suspects were apprehended in two coordinated operations by the military police and the border guard units in Elbeyli, in the southeastern province of Kilis, near the Syrian border.

In the first operation, seven unidentified foreign nationals were caught in Beşiriye village, near the town of Elbeyli, as they tried to cross into Syria.

In the second, also backed by anti-terror police and special operations forces, two people allegedly connected to ISIL were apprehended before they were able to cross the border.

The two suspected ISIL members were arrested when they were sent to the court house after being questioned by the Elbeyli police. The seven others were referred to the court house after interrogation by the military police.

Twenty-five police officers including a deputy police chief were rounded up during the operations, which were carried out in several provinces at 6 a.m on Thursday, Nov. 6.

The deputy police chief, Kenan Gök, from the Gaffar Okan Police Academy in Diyarbakır, was detained under instruction of the Kilis prosecutor’s office and dispatched to Kilis for interrogation. Gök had been appointed to the Academy as an instructor.