The German Federal Police are investigating several Afghans who entered the country with a promise of admission for possible document fraud.

Preliminary investigations have been launched in eight cases for document fraud, the authorities said on Thursday evening. The cases mainly involve forged or falsified documents, DPA reported.

A plane chartered by the German government carrying 138 Afghan nationals granted admission to Germany touched down in the eastern city of Leipzig on Wednesday evening.

The plane took off from Pakistan’s capital Islamabad.

“We can confirm that the particularly endangered persons from Afghanistan who arrived yesterday from Pakistan have been subjected to entry checks and that preliminary investigations have been initiated,” a spokesman for the Federal Ministry of the Interior told the German tabloid Bild.

Four people were killed after the car they were travelling in collided with a truck in Afghanistan’s central Maidan Wardak province on Thursday night, local authorities said.

The incident happened on Kabul-Kandahar highway in Sayedabad district of Maidan Wardak, provincial police said in a statement.

All four people in the car were killed in the incident, it said.

Zabihullah Hakimi, spokesman for police in northern Takhar province, was also among the dead.

An Afghan teenager accused of taking part in an Oklahoma plot to carry out an Election Day attack has pleaded guilty, federal prosecutors said Thursday.

Abdullah Haji Zada, 18, a citizen of Afghanistan who was living in Moore, Oklahoma, pleaded guilty to knowingly receiving and conspiring to receive a firearm and ammunition to be used in a terrorist attack, court records show, the Associated Press reported.

Zada, who was 17 at the time of his arrest, is awaiting sentencing and faces up to 15 years in prison and a $250,000 fine. Zada also agreed to be removed from the United States after he is released from prison, court records show.

Telephone and email messages left on Thursday with Zada’s attorney, Jeff Byers, were not immediately returned.

Zada’s co-defendant, Nasir Ahmad Tawhedi, 27, who previously worked as a security guard for an American military installation in Afghanistan, is currently awaiting trial for conspiring and attempting to provide material support to the Islamic State group.

Prosecutors allege Zada and Tawhedi took steps to obtain AK-47 rifles and ammunition and planned to carry out an attack targeting large crowds on Election Day last year.