Android :: Center Two Buttons Horizontally

I try to arrange two buttons (with images on them which work fine) next to each other and to center them horizontally. That's what I have so far:
<Linear Layout android:orientation="horizontal" android:layout_below="@id/radioGroup"
android:layout_width="wrap_content" android:layout_height="wrap_content"
android:layout_gravity="center_horizontal|center">
<Button
android:id="@+id/allow"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/radioGroup"
android:layout_gravity="center_horizontal"
android:drawableLeft="@drawable/accept_btn"
android:text="Allow"/>
<Button
android:id="@+id/deny"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toRightOf="@id/allow"
android:layout_below="@id/radioGroup"
android:layout_gravity="center_horizontal"
android:drawableLeft="@drawable/block_btn"
android:text="Deny"/></LinearLayou?