Is it accessible to have lists without a heading, assuming previous lists do?

Assume this HTML structure:

<h2>Our latest News and Events</h2>
<ul>
  <li>news item 1</li>
  <li>news item 2</li>
  <li>news item 3</li>
</ul>
<ul>
  <li>event item 1</li>
  <li>event item 2</li>
</ul>

My question is whether the above structure is accessible and good enough, or whether I should merge the 2 lists into one so it becomes:

<h2>Our latest News and Events</h2>
<ul>
  <li>news item 1</li>
  <li>news item 2</li>
  <li>news item 3</li>
  <li>event item 1</li>
  <li>event item 2</li>
</ul>

Notes:

• In both cases the heading semantically covers all subsequent items (news and events).
• I cannot change any of the content, nor add any new headings. The data is given as is, so I can only affect the HTML (i.e combine the two lists in one).
• Both cases would have the exact same presentation (i.e there wouldn't be a visible gap between the 2 lists in the first case).