This refers to the Prophets that the Israelites killed. The charge is repeated in for example:
ذلك بأنهم كانوا يكفرون بآيات الله ويقتلون النبيين بغير الحق
That was because they disbelieved in the signs of Allah and killed the prophets without right.
— Quran 2:61
فريقا كذبوا وفريقا يقتلون
a party they denied, and another party they killed
— Quran 5:70
The fact that the Israelites killed some of their Prophets is attested to
In the Tanakh itself:
And he [Elijah] said: "I have been zealous for the Lord, the God of Hosts, for the children of Israel have forsaken Your covenant. They have torn down Your altars and they have killed Your prophets by the sword, and I have remained alone, and they seek my life to take it.
— 1 Kings 19:10
And they disobeyed and rebelled against You, and they cast Your Law behind their backs, and they slew Your prophets who warned them, to bring them back to You, and they committed great provocations.
— Nehemiah 9:26
And the Gospel:
So you testify against yourselves that you are the descendants of those who murdered the prophets.
— Matthew 23:31
Jerusalem, Jerusalem, you who kill the prophets and stone those sent to you.
— Luke 13:34
A comprehensive list of their names is not mentioned in either scripture.