pthread_join Segmentation fault

I am trying to use pthread_join with this producer-consumer program but I keep getting a segmentantion fault. My purpose is to wait for all the producer threads to end and then terminate all the consumers. But after the first thread joins I get a segmentation fault. I searched the web but haven't found anything useful. Any Ideas?

#include <iostream>
#include <pthread.h>
#include <vector>
#include <cstdlib>
#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include <semaphore.h>
#include <string.h>
#include <unistd.h>


#define BUFFER_SIZE 10

void *Produce(void *);
void *Consume(void *);
int InsertItem(int);
int RemoveItem(int *);

int iCounter;
pthread_mutex_t mutex;
sem_t full, empty;

  std::vector<int> buffer(BUFFER_SIZE);


using namespace std ;
int main()
{
  pthread_mutex_init(&mutex , NULL);
 sem_init(&full , 0 ,0);
 sem_init(&empty , 0 , BUFFER_SIZE);
  pthread_t ProducerThread , ConsumerThread;

 int *aa = new int [4];
 for(int i = 0 ; i < 4 ; i++)
 {
  aa[i] = i;
  pthread_t t;
  int k= pthread_create(&t , NULL, Produce , &aa[i]);
  if(k!=0)
  cout<<"Errot"<<endl;
  else  
  printf("Creating Producer %d \n", i);
 }
 int *bb = new int[2];
 for(int i = 0 ; i < 2 ; i++)
 {
  bb[i] = i;
  pthread_t t;
  pthread_create(&t , NULL, Consume , &bb[i]);
  printf("Creating Consumer %d \n", i);
 }
int s;
  for (int i=0;i<4;i++){
  s = pthread_join(aa[i],NULL);
               if (s != 0)
                   cout<< "pthread_join error" ;}


 sleep(5);
 delete [] aa;
 delete [] bb;
 for (int j=0;j<iCounter;j++)
  // cout<<buffer[j];
 return 0;
}


void * Produce(void * Param)
{
 int item;


    for (int i=0;i<5;i++)
  {

  int t = rand() % 1000;
  usleep(t);
  item = rand() % 100;
  sem_wait(&empty);
  pthread_mutex_lock(&mutex);
  int iMsg = InsertItem(item);

  if(iMsg == -1){
   printf("Error Inserting Item \n");
  }else
  {
   printf("Produced Item :: %d  Thread No :: %d\n", item , *((int *)Param));
  }
  pthread_mutex_unlock(&mutex);
  sem_post(&full);
  }
 }


void * Consume(void * Param)
{
 int item;

 while(1)
 {
  int t = rand() % 1000;
  usleep(t);
  sem_wait(&full);
  pthread_mutex_lock(&mutex);
  int iMsg = RemoveItem(&item);

  if(iMsg == -1){
   printf("Error Removing Item \n");
  }else
  {
   printf("Consumed Item :: %d  Thread No :: %d \n", item ,*((int *)Param));
  }
  pthread_mutex_unlock(&mutex);
  sem_post(&empty);
   }
}


int InsertItem(int item)
{
 if(iCounter < BUFFER_SIZE)
 {
  buffer.push_back (item);
  iCounter++;
  return 1;
 }
 else{
  return -1;
 }

}


int RemoveItem(int *item)
{
 if(iCounter > 0)
 {
  *item = buffer[0];
  buffer.erase (buffer.begin());
  iCounter--;
  return 1;
 }
 else{
  return -1;
 }
}