A prosecutor said police this week arrested three men from Moldova and a Syrian Kurdish couple this week.
Bulgarian prosecutors are indicting five people for aiding “terrorists” in connection with an explosion in central Istanbul that killed six people on November 13, chief prosecutor Ivan Geshev said on Saturday.
Bulgarian special police arrested three Moldovan men and a Syrian Kurdish couple this week following an investigation and close cooperation with Turkish prosecutors, Geshev told Reuters.
“Five people have been charged. The crimes are in two categories: supporting terrorism in another country, the attack in Istanbul, and human trafficking,” said Geshev, adding that he was involved in human trafficking through Turkey and smuggling.
A Bulgarian court ruled in a closed case on Saturday that the four men should be held in prison before trial on human trafficking charges, saying there was not enough evidence to jail them on charges of supporting terrorism.

Prosecutors did not ask the court to sentence the woman to prison due to illness.
In Chisinau, the Ministry of Foreign Affairs of Moldova confirmed that three citizens have been arrested.
“Our country strongly condemns any terrorist act, including what is happening in Istanbul,” said ministry spokesman Daniel Voda.
The Turkish opposition has already called for the extradition of some of those suspected of involvement in the bombing, Geshev added.
On Friday, a Turkish court ordered 17 suspects to be held in prison pending trial, charging them with anti-government cooperation, premeditated murder and attempted murder. Among them was the suspected bomber, who police identified as Ahlam Albashir from Syria.
No group has claimed responsibility for the explosion, which also injured more than 80 people on Istiklal Avenue, a busy and historic pedestrian area.
Turkish officials blamed the attack on the Kurdistan Workers’ Party, or PKK, and allied Syrian Kurdish groups. Kurdish groups refused to participate.
The attack was the deadliest in five years and brought to mind the horrors of bombings across the country between 2015 and 2017 that were mainly carried out by Kurdish forces and ISIL (ISIS).