Encountering race condition using openMP in C - c

Question

Here is the section of my code where I am running into a race condition. I'm just trying to copy the values of the matrix "matxOriginal" into the matrix "cluster0", but, when run on multiple threads using openMP, the sample values printed for "cluster0" is different from "matxOriginal".
Both matrix has been dynamically allocated and are both 698 x 9 matrix.
Also, I would like to keep the use and purpose of the "cluster0IndexCounter" variable for a different use outside of what I'm posting. So if you can, please let me know how to make this work.
double **matxGen(int row, int col)
{
int i=0, j=0;
double **m;
m=(double **) malloc(row*col*sizeof(double *));
for (i; i<row; i++)
{
m[i]=(double *) malloc(col*sizeof(double ));
for (j=0; j<col; j++)
{
m[i][j]=j+i;
}
}
return m;
}
double **emptyMatxGen(int row, int col)
{
int i=0, j=0;
double **m;
m=(double **) malloc(row*col*sizeof(double *));
for (i; i<row; i++)
{
m[i]=(double *) malloc(col*sizeof(double ));
for (j=0; j<col; j++)
{
m[i][j]=0.0;
}
}
return m;
}
int main()
{
int x, i, j, tid, row=699, col=9,
cluster0IndexCounter=0;
double **matxOriginal, **matx, **cluster0;
matxOriginal=matxGen(row, col);
matx=matxGen(row, col);
double *centerPoint0=matx[99];
cluster0=emptyMatxGen(row, col);
#pragma omp parallel for private(x, j, tid) schedule(static) reduction(+:cluster0IndexCounter)
for (x=0; x<=698; x++)
{
for (j=0; j<9; j++)
{
cluster0[cluster0IndexCounter][j]=matxOriginal[x][j];
}
cluster0IndexCounter=cluster0IndexCounter+1;
}
printf("cluster0: %f, %f, %f, %f, %f\n", cluster0[9][0], cluster0[9][1], cluster0[9][2], cluster0[9][3], cluster0[9][4]);
free(cluster0);
free(matxOriginal);
free(matx);
return 0;
}