Belgium is asking Greece to extradite a detainee suspected of involvement in a terrorist plot against Belgian police officers, prosecutors in Brussels said Sunday. The BBC reported Greek and Belgian authorities have been cooperating on an investigation into suspected jihadist cells as part of a larger crackdown on terrorist plots in the wake of this month’s shootings in Paris.

Greek officials said Saturday they had arrested four people in Athens with alleged terrorist ties, including a man matching the description of Abdelhamid Abaaoud, a 27-year-old Moroccan-born man Belgian authorities said was connected to a plot against Belgium police. It was not clear if that man is the one Belgian officials targeted for extradition.

Earlier Sunday, Belgian officials denied there was any link between the detainees in Greece and the terrorist scheme, but later said additional information prompted the request. “Further analysis of the elements of our investigation gave us enough reasons to ask for the extradition of one of the persons that were arrested yesterday by the Greek authorities,” Belgium's federal prosecutor’s office said in a statement Sunday.

Belgian police launched a raid in the city of Verviers Friday, targeting people suspected of planning the attack on police. Two suspected militants died in a shootout that followed.

Security forces across Europe have been escalating counterterrorism operations in the wake of the Paris attacks that left 17 people shot to death little more than a week ago. However, officials in Brussels have said there is no connection between the terror plots in Belgium and the Paris shootings. Still, authorities across the continent have been on alert, looking to root out jihadist plots amid fears of terrorist sleeper cells. Police in Belgium, Ireland, France and Germany have arrested more than 30 people in the last week as part of the anti-terror sweep.